RECAP | Star Trek: Discovery 506 - 'Whistlespeak'

Previously, Dr. Hugh Culber confides in Sylvia Tilly that his experiences on Trill, , along with their quest to find the thing that created them has been weighing heavily on him. Plus, Paul Stamets hates the unknown; they've always sought out answers together, but he doesn't know how to talk to his partner about any of this. Meanwhile, Adira feels immense guilt for bringing the time bug aboard the ship and trapping the ship in a time loop.

on the I.S.S. Enterprise; Captain Michael Burnham secures the next clue, while L'ak made a bad call and ends up severely wounded. With the clue in Discovery's possession, Stamets begins running a full chemical analysis of the vial found within the clue.

In Episode 6 of, "," while undercover in a pre-warp society, Captain Burnham is forced to consider breaking the Prime Directive when a local tradition threatens Tilly’s life. Meanwhile, Culber tries to connect with Stamets, and Adira steps up when Rayner assigns them a position on the bridge.

A polychromatic glow envelops the U.S.S. Discovery-A's Engineering section as Commander Paul Stamets places the vial retrieved from the I.S.S. Enterprise into the scanner for analysis. He is joined by Captain Michael Burnham and Lieutenant Sylvia Tilly, and they all remain frustrated that the clue has stalled them for two days. A hundred other tests have already yielded the same result — the vial's composition is generic and the water inside is pure, inert, distilled… and wet. Burnham notes a scratch on the container and wonders if the damage might indicate that a piece is missing. The modified spectral analysis is completed, but Tilly dejectedly announces that the fluid still reads as distilled water. 

The room's illumination is raised to normal levels as the captain begins to pace around the sample. The other clues had words and symbols, yet Stamets assures her that his review of scans from the Enterprise did not reveal signs that anything else was ever affixed to the vial. An attempt to fabricate the map's final two pieces also failed, so solving this clue is the key to finding the next two and reaching the Progenitors' power. Burnham suggests they pivot from chemistry and try history and anthropology — planets where distilled water had cultural or symbolic significance 800 years ago, as well as worlds with severe droughts that would have required rainwater alternatives.

Captain Burnham beams out of Engineering for a scheduled meetup with Dr. Kovich in the sterile confines of the Infinity Room. She assumes he brought her here because there is a new lead on Moll and L'ak, but Kovich sits at a desk and informs her that the U.S.S. Locherer is handling the search. Finding the Progenitors' tech is the Discovery's mission, and Kovich appears dissatisfied with their lack of progress in tackling the most recent clue. The scientists who hid the technology's location each made their own piece of the clue trail in secret, so Kovich proposes that each individual likely employed their own expertise in the process. He slaps a 20th Century legal pad on the table, having demonstrated his resourcefulness by recovering the scientists' names. The eccentric man tears off a sheet of paper — genuine, not replicated — and hands it over to the captain.

In his office aboard Discovery, Dr. Hugh Culber converses in Spanish with a holographic representation of his abuela. He requests the recipe for their mofongo so he can make it for Paul, but his abuela laughs off the notion. The dish they made was inedible. When Culber would fall asleep, she would throw out their concoction and replicate the food instead. He asks Zora to pause the program and send a message to Dr. Pollard; they might be onto something with this grief alleviation therapeutic, as the brainwave patterning is incredible and the holo of his grandmother is exactly as he remembers her.

Culber's joyful expression fades to uncertainty, and he has Zora restart the program. He mentions his experience with the to her and underscores an indescribable feeling that has emerged in its aftermath. She cradles his face with her hands but cannot help him understand it. They had often spoken about her spiritual practices, so her inability to answer confuses Culber. His abuela speaks up, clarifying that she trained him to be a doctor — a man of science. She questions how he can consider the soul when he has not examined the body, and Culber's features light up with inspiration and comprehension.

Captain Burnham presents Kovich's list of the scientists' identities and homeworlds to Tilly and Stamets in Engineering. Three names are crossed off — , , and the — leaving Marina Derex of Betazed and Hitoroshi Kreel of Denobula. Burnham bets that the vial is related to Dr. Kreel, whose specialty was designing weather modification towers to generate rain. Denobulan weather towers seed clouds with silver iodide, but the vial's water is free of contaminants. Kreel also did work for other worlds, and especially arid planets would need to extract water from the air at a molecular level. Zora relays that there were 15 M-class worlds on Denobulan trade routes in Kreel's lifetime, but only one — Halem'no — had needed to harvest water in that way. The breakthrough earns a smile from the captain.

Discovery jumps into orbit around Halem'no, where a lush green region stands out from the rest of the planet's bare surface. Long-range scans show a Denobulan weather tower that manufactures rain and emits a low-grade force field to shield the lone habitable region from dust storms. On the Bridge, Commander Rayner is curious as to why Kreel would make such a tower look like a mountain, so the captain turns to Ensign Adira Tal at their science station. Nervous to be assigned to such a prestigious duty, Adira reports that pre-warp and pre-industrial humanoids inhabit the protected area. Given the lack of an electrical grid and surveys which show the storms have increased in severity over the years, they posit that Kreel hid the tower so as not to violate the Prime Directive.

Burnham and Rayner are pleased by Adira's response, and the first officer tells the captain that he honored the ensign's request for more time on the Bridge because he felt they were ready. Adira isn't so sure, but Rayner declares that there's no time like the present. Burnham emphasizes the need to abide by the Prime Directive and conceal their technological capabilities from the locals. An unusual energy field around the tower prevents beaming in or scanning for the next clue, so Burnham states that she'll head to the surface with Tilly while Rayner commands the ship.

A soothing whistle fills Discovery’s Science Lab, where the captain researches the "whistlespeak" component of the Halem’nite language. Tilly enters, and both officers are now dressed in attire that will allow them to fit in on the planet. Zora can convert the whistlespeak into Federation Standard, but the Halem'nites don't always whistle. They have a phonetic language for day-to-day interactions, but the whistlespeak lets them communicate across great distances. The ability to learn about a society by how its individuals speak sparks enthusiasm from the captain’s inner xenoanthropologist. The Halem'nites don't have any terms to denote societal status or class, but they do recognize three distinct gender identities and prize connection with one another. Amazement washes over her and evokes memories of her time in Dr. T’Prasi's xenolinguistics seminar on Vulcan.

Tilly is thrilled by Burnham;s happiness and comments that they could really use her at Starfleet Academy. The captain asks her friend how things are going there, but their chat is postponed by an update from Rayner. Subcutaneous comms have been loaded into the transport system, and Ensign Tal has included Starfleet's latest retinal tricorder mod. Burnham thanks the commander and beams down alongside Tilly. They materialize in a quiet forest under the cover of night and marvel at the size of the tower constructed by Kreel, which the locals refer to as the High Summit and visit in an effort to commune with their gods.

The two officers begin walking to their destination, and Michael revisits the chat about Starfleet Academy. Tilly just received a message from Cadet Ross, one of her students who had served drinks at the Millennium Celebration. Ross is considering leaving the Academy to accept a position on a cargo vessel, so she wanted Tilly's advice on the matter. Aware that Ross isn't the first cadet to be confronted with this dilemma, the lieutenant is unsure how to respond. Tilly voices her concern that the Academy isn't providing what the cadets need, but she turns her attention to the sound of whistlespeak resonating through the woods. The universal translator deciphers the exchange — travelers from the dust storms are being greeted with hospitality in the direction of Burnham and Tilly's destination.

Back on Discovery, Cleveland "Book" Booker catches up with Dr. Culber in a corridor and expresses his desire to contact the ship's counselor on the Locherer. While Book wants to brief them on Moll and L'ak's full background, Culber insists he must accept there's nothing for him to do right now. The doctor urges Book to focus on something that will allow him to recharge himself, and the former courier playfully ponders whether Culber ever gets tired of having all the answers.

Culber continues to Engineering, where he discovers Stamets toying with the three interlocking clues that have already been recovered. He consults his partner about his desire to do a full neural scan on himself, a revelation which instantly generates a worried look on Paul's face. Culber guarantees that everything is fine and he merely wishes to collect data on the neurological aftereffects of zhian’tara. Stamets realizes Hugh's interest likely stems from real-world symptoms, and the doctor reluctantly confesses that aftereffects might be present. Optimistic about the opportunity to work together — "nothing as romantic as a neural scan" — they express their love through a kiss and resolve to get to work in the morning.

On the surface below, Burnham and Tilly introduce themselves to the group of compeers they had heard from afar. They're greeted warmly, though an elder compeer, Anorah, suffers from a severe cough caused by a dust storm in the drylands. Those gathered proceed toward the High Summit and listen as the elder shares her selfless story of risking time in the storms so that another would not have to take her place. A lengthy drought has been upon them, but the elder points out that only the chosen devout may enter the High Summit's temple to pray for rain. The captain claims that she has come from the east and lived too far away to have witnessed the Summit before.

A friendly voice calls out to the travelers, and a young compeer named Ravah approaches them bearing a smile and holding a lantern. As they welcome the group, their cordiality transforms into concern for the elder, who has begun coughing once again. They head to the healing grove and rest the elder on a wooden bed, but her medicine is nowhere to be found. Alone for the moment, Burnham and Tilly quietly analyze the situation — a sonic percussion wave would easily dislodge the dust in the elder's lungs, but breaking the Prime Directive is not an option. They roll their patient onto her side and administer compressions to her back.

Ravah's father rushes over, and Ravah distributes metal bowls to everyone present. They form a tight circle around the elder and use pestle-like tools on the dishes to generate a high-pitched sound wave. The vibrations rattle nearby surfaces and permit Anorah to cough up dust, but their power overwhelms the captain and renders her unconscious. Burnham awakes a short time later on a bed of her own, pleased to see that the elder has survived. Ravah's father is seated by her side and apologizes for not warning her about the intensity of the sound cure.

Tilly and Ravah join them, and the young compeer shares that their father Ohvahz — the Priest of the Summit — brought them to this settlement after their mother died. They are eager to take their turn and clear dust on the frontlines, though their father is less enthusiastic about the prospect. He is perplexed by Burnham's desire to enter the temple and proclaims that she does not need to do so in order to give thanks to the gods. Ravah eagerly chimes in, stating that one can get in by completing the Journey of the Mother Compeer — a grueling race and test of devotion which makes the gods happy. Only the victor is worthy of going inside the temple and asking for the gods' blessing. To the priest's chagrin, Burnham makes a formal request to partake in the Journey.

The next morning, numerous participants assemble at the base of the Summit. The atmosphere is festive, and Ravah lightheartedly teases that they are destined to win the race. Their father is clearly concerned about their decision to partake in the event, arguing that they are too young to take the journey. Ravah wears their mother's bracelet in the hopes that she will watch over them, but the priest remains distressed. Tilly steps forward, noting that Ravah's voracity is reminiscent of one of her students "back east." As a teacher, it can be difficult to step back, and she can't imagine how arduous it would be as a parent. Ravah heeds the advice and admires their father, but wants to show him that they can be great too.

Burnham approaches and asks to speak to Tilly for a moment, and the two officers move away to discreetly communicate with Discovery's Bridge. Rayner gives the stage to Adira, whose scans led them to believe that Halem'no might have had other weather towers in the past. A team of DOTs scoured the surface and located four more towers — over time, their energy distribution matrices fell out of alignment. The High Summit is experiencing the same effect, and that failure is producing the energy field surrounding the tower. Finding the auxiliary control panel would allow them to correct the problem by resetting the components. If they don't fix the technology, those living near the High Summit will perish — just as the settlements surrounding the other towers had. Burnham resigns herself to the truth that one mission has become two.

In Discovery's Sickbay, Culber sits up on a biobed as Stamets divulges that no biological, chemical, or genetic anomalies appear in the doctor's brain scan. The astromycologist quips that his partner has a perfectly typical, healthy, and — glimpsing the holo of Culber's results — rather handsome human brain. No lasting neurological effects of the zhian'tara are detected, yet Hugh is disappointed that the scans have not provided a physiological cause for what he's feeling. Ever since Trill, he has felt more connected and attuned to something greater than himself. Paul reasons that it's a spiritual quandary, and the doctor nods. Stamets looks on the bright side by highlighting Culber's health and suggests he just enjoy the sensation. He pronounces that the human brain is one of the most complex things in the known universe and places a reassuring hand on the doctor's arm.

On Halem'no, Captain Burnham approaches Anorah who she helped save the previous night. Unlike those excited by the prospect of the race, this compeer reflects on the journey she and her friend Vohrahli had participated in during their youth. Vohrahli won, but the compeer wonders what it’d be like if she and her friend could be wrinkled old elders together. She shares a laugh with Burnham then observes that one doesn't need to go to the High Summit to be with the gods — they are with them when they do good for each other, just as Burnham saved her — though she accepts Burnham's determination to run.

The captain makes her way over to Tilly at the starting line, and the priest regales the runners with the legend of the Mother Compeer as they are each given a cube to consume. In ancient times, warring Halem'nites lost the favor of the gods and were punished with the dust storms. The Great Mother Compeer rescued her people from thirst by showing the gods the Halem'nites' true selves and venturing out into the storms to find water — as he speaks, several competitors begin coughing and grasping at their throats. The Mother Compeer's lungs filled with dust on her journey home, but she resisted the urge to drink, saved the precious liquid for her children, and died in the process. The gods were so moved that they brought back the rains.

The cube's deleterious effects take hold of Burnham and Tilly, a dry cough and terrible thirst manifesting as compeers fill bowls of temptingly refreshing water on pedestals. The Journey replicates the trial the Mother Compeer endured in a bid to earn the gods' merciful rain. Two compeers can't bear their discomfort any longer and drink from the nearby bowls. Ravah taunts their friends, and the two Starfleet officers take off as the competition begins. The runners jog through the Summit's trails, and several are disqualified when they imbibe from the water dishes they pass along their route.

Slightly winded, Captain Burnham pauses to rest as Tilly circles around her. They press forward, but Michael notices some of the blue moss on the side of the trail has turned yellow. Aware that such a genetic mutation could be caused by radiation leaking out of the tower's malfunctioning control panel, Burnham expects the path of yellow moss to guide her to the controls. In case she's wrong, Tilly — the Queen of Endurance — will stay in the race. The lieutenant is emboldened by the mantra "a body in motion remains in motion," while the captain refreshes herself on the nearest bowl of water.

Further up the Summit, Tilly's exhaustion almost leads to her collapse, but Ravah hurries back to motivate their friend. As the only two runners left, they volley competitive banter back and forth before resuming their jog. Meanwhile, Burnham pursues the yellow moss to a boulder, her retinal tricorder glowing blue as it scans the object's surface. There is a mechanism inside, and pressing the large rock's exterior opens an access panel. The captain alerts Discovery and transmits a holo schematic of the controls to Adira, who informs her that she'll need to rebuild the motherboard without shutting it down. The ensign directs Burnham to a red isolinear chip among a sea of others, and she commences swapping them out.

Creeping ever closer to the finish line, Ravah and Tilly are forced to carry bowls of water to symbolize the relief that tempted the Mother Compeer. They resist the tantalizing liquid, but Ravah is disqualified when they stumble and spill their dish. The priest pleads with them to drink, but Tilly retreats and fills Ravah's bowl with some of her own water. They stand and lock arms, completing the race together as the other compeers clap and cheer them on. 

Adira and Discovery's Bridge crew listen to their captain's updates from orbit, and Rayner addresses the ensign's lingering doubts. He affirms that the time bug was not their fault, encouraging them to tell Burnham the last step in the repair process and "bring it home." The panel's lights shut off when Burnham yanks out the auxiliary power circuit, but the controls hum to life moments later. Adira is elated, and the captain is able to contact Tilly, who has entered the temple with Ravah. There are no signs of the clue, but with the energy field now gone, Discovery can beam a team over.

Tilly's attention is drawn to the voice of Ravah's father, Ohvahz, who comments that their sacrifice will bless Halem'no for many seasons to come. The phrasing startles Tilly, and the young compeer returns their mother's ornate bracelet to their father. As he strains to hold back his tears, Burnham orders Tilly to get out of there. However, when the priest departs the room, the door is sealed and prevents the lieutenant from being transported out. Thick stone walls descend around the Summit's windows, trapping them both inside the temple.

Burnham, Tilly, and Discovery's Bridge crew attempt to find a workaround, but the walls are solid tritanium and too dense for a transport lock. Rayner pulls up a temple schematic — Tilly is in the vacuum chamber where chemicals rise to mix with air and be shot into the atmosphere. The reaction produces rain, but all the oxygen will be sucked out of the room. Ravah overhears Tilly coordinating with the ship, but the lieutenant remarks that she is praying to the gods. More stone slabs cover the light shining in from above, draping the chamber in darkness. Although Ravah expresses gratitude for Tilly's help in getting here, the Starfleet officer is distressed by her role in the young compeer's impending sacrifice.

As Ravah takes Tilly to pray by the serenity wall, Captain Burnam has Discovery beam her as close to the temple as possible. A lifesign — Ohvahz — is detected in the control room next to the vacuum chamber, and Rayner raises concern about the Prime Directive. Burnham repeats her order to transport her over. Weakened by the lack of air, Tilly asks Ravah about the symbols carved into the temple's wall. They are numbers which represent the five serenity prayers. Ravah translates the ancient Halem'nese, stroking their hand across the symbols for "one," "two," and "three" — they are in the third Summit. Tilly turns to the markings for "four" and "five," suddenly realizing that the fifth symbol looks very familiar.

Ravah continues to speak about sacrifice, but they withdraw from the wall to kneel on the floor. They cry to themselves, overcome by the reality of death. They admit they do not wish to die, and Tilly moves to comfort them by cradling them in her lap. Tears also pour from the eyes of the priest, who prays to Ravah's mother in the control room and apologizes for failing to protect their child. Burnham materializes behind him, her unorthodox entrance inspiring confusion and fear in the Halem'nite. Urgently needing him to open the door to the chamber, the captain tries to reach him by explaining that they are standing inside of a machine. This gains his attention, and Burnham clarifies that the sacrifices don't bring the rain, the technology does.

The momentary connection between them evaporates into disbelief, prompting Burnham to hurry to the door and frantically search for the mechanism to activate it. Tilly overhears their discussion through the comm channel and asks Ravah what they remember about their mother. The young compeer hums a song their mother sang to help them sleep. The captain seizes the chance and hums the tune to Ohvahz, who instantly recognizes it. Shocked, he listens to Burnham's words once again — technology allows her to hear his daughter in the other room, and they don’t want to die.

Burnham makes it clear that she is a person, not a god, and she has come from far away to help. The rains will come whether or not Ravah perishes, and she requires his assistance to ensure they live. Ohvahz springs into action, extracting a control handle from the floor and rotating it. The temple is filled with the rumble of stone in motion, and air streams into the vacuum chamber. Burnham and the priest scramble over to their unconscious companions, and Dr. Culber beams in to resuscitate Ravah.

Soon after, Ohvahz marvels at a holographic depiction of Halem'no and is struck by its beauty. Crouching by Ravah, Culber signals that the young compeer will recover. Though relieved, the priest must now confront the Summit's true origins. Burnham details the value the Denobulans place on one another, and much like Halem'no, the massive storms of Denobula required them to build weather towers in order to survive. She supposes the Denobulans felt a connection to the Halem'nites during their travels. The tower will stop functioning eventually, but Burnham will teach them how to maintain it.

The priest is appreciative, but questions whether or not his gods are actually real. The captain counters, stating that nothing she has shown him proves that gods do not exist or that the Journey of the Mother Compeer did not occur. It simply means there are also people from other worlds. Concerned about what to tell his people, Ohvahz is uncertain how they can find a common purpose without the sacrifices. Burnham references Anorah, the woman he healed, who appeared ready to move beyond the sacrifices. Beliefs can evolve, and maybe more Halem'nites are prepared to understand that. Dr. Culber informs them that Ravah will wake soon, and their father moves to put their mother's bracelet back on his child before they stir.

Burnham converses with Tilly about her Prime Directive violation, but the lieutenant has insight that will improve the captain's mood — the symbol for "five" on the temple's Serenity Wall matches the scratch mark on the vial of distilled water. The next clue must be in Tower Five! They turn as Ravah calls for their father, who settles their concern about defying their faith by saying, "Perhaps devotion means being able to hear when the gods tell us something new." He boasts about the pride he feels for them, and they embrace. A roar of thunder clatters above them, and a wealth of rain falls on the entire region.

Parked in a shuttle aboard Discovery, Book tests his piloting skills in a flight simulation. The program ends when Culber enters carrying two covered dishes, the doctor having brought his grandmother's mofongo con pollo al ajillo — replicator fresh. They take a seat to dine, and Book savors the delicious smell. Culber brings up Book's joke that the doctor has all the answers and vows that he does not. As they both enjoy the food, Culber notes that he's either having a "spiritual awakening" or seeing a truth he's always known. Book believes it sounds kind of wonderful and asks why Hugh is upset that Paul may never understand this feeling. Humans have an odd quirk — a tendency to consider something to be less meaningful if it's just for yourself. Book recalls Michael dealing with a similar struggle, and Culber can see that the former courier misses what he had with the captain. It's unknown whether the two can get their relationship back.

Having recovered the next clue from Tower Five, Burnham and Tilly lock it into the map alongside the three previous pieces. The latest device had a metal card attached featuring a Betazoid text inscription. Stamets is currently analyzing the writing, so the two officers take a breather in Engineering and theorize about what Dr. Kreel had intended to teach them with his clue. The scientists couldn't have known the weather tower would lead the Halem'nites to sacrifices, but the lesson may reside within the notion that technology is a massive responsibility. When Discovery finds the ' creation, its crew will need to be incredibly careful. Lieutenant Christopher contacts them over the comm system, relaying that the U.S.S. Locherer just found Moll and L'ak. Admiral Vance wants Discovery to jump there immediately. As the starship leaves orbit and activates its spore drive, the serene sound of whistlespeak echoes out from the planet.