Episode 3 of Constellation begins with an intense scene, as Jo and Alice venture through the snow, heading towards the distant cabin. The fierce snowstorm quickly envelops them in a dense fog, and Alice suddenly loses sight of Jo amidst the swirling whiteness.
Flashing back to a different time, Jo lies in a hospital bed, surrounded by concerned faces. Alice watches anxiously, fretting that her friend doesn't seem like her usual self. Later, the spotlight turns to Jo as she steps into a press conference, her voice confident as she declares her happiness to be back home. She speaks wistfully about the familiar scent of Earth, a reminder of the world she's returned to.
Afterwards, the astronauts gather around Wendy and her mother, Frida. But in a moment of awkwardness, Jo mistakenly calls Frida by the wrong name, Erica, a slip of the tongue that belies her exhaustion.
Meanwhile, in the Stark City labs of Russia, Henry pores over his data with his colleague, showing him the puzzling results from the CAL. He explains that he extracted the data immediately after it was retrieved from the evacuation capsule, and initially, the results matched Paul's initial findings. But now, something has changed, and the results no longer align. His colleague is skeptical, finding it hard to believe in the shifting nature of the data.
Elsewhere, Bud Caldera finds himself on a ship, attending a space convention. He grudgingly sets up a table, signing pictures for fans who seem unaware of his disgruntled demeanor.
A meeting is convened, bringing together astronauts and professionals from various space agencies, all gathered in Russia. The discussion turns to the mysterious accident on the ISS, and Jo recounts her belief that the collision was caused by a mysterious body. But her colleagues brush off her claims, chalking them up to hallucinations induced by oxygen deprivation. Later, Jo's recovery continues with rigorous treadmill sessions and a daily regimen of pills.
Henry's debate with his colleague, Eryn, continues to intensify. He insists on what he saw when he extracted the data from the core, but Eryn remains unconvinced, declaring it impossible.
At the Russian accommodation for the European Space Agency, Jo and Magnus share a tense dinner. Jo worries that Alice, who seems out of sorts, has forgotten her Swedish.
On the ship, Bud becomes embroiled in a heated debate as part of the program. The host accuses him of falsifying his account in his book, claiming that his mission to the moon is riddled with inaccuracies.
Meanwhile, Henry finally achieves a breakthrough. On his computer, he sees the same mysterious pattern he'd glimpsed before - two pulsating circles. But his phone camera is unable to capture the image, forcing him to rely on his own hand to draw a replica of the bizarre sight.
Back in the snow, Alice struggles to help Jo walk, her footing suddenly giving way. As Alice rushes to fetch Magnus, Jo notices that she's standing in the same passageway, with a wooden cupboard looming at the end. The scene is fraught with tension, as the episode reaches a cliffhanger, leaving the viewer eager for the next installment.
Henry and Eryn are locked in another argument, squabbling over what Henry witnessed on the computer screen. Amidst their bickering, Henry's gaze drifts to Alice and Wendy, engrossed in a game of hide and seek. Alice takes cover, only to witness Wendy casting her beloved stuffed rabbit into a puddle and stamping on it viciously. Alice rushes out, enraged, accusing Wendy of the deed, but Wendy adamantly denies any wrongdoing. The quarrel erupts, and following the dust-up, Alice discovers to her amazement that her rabbit remains pristine, free of any traces of water or dirt.
Meanwhile, Jo persists in her insistence that she spied the corpse of a USSR astronaut during the meeting with the space agencies. Her companions refute her claims, insisting that every USSR astronaut has been accounted for. They chalk up the collision to some stray space debris. Deflated, Jo returns to her quarters at the ESA accommodation. She confides in Magnus her feelings, professing her love for him before planting a kiss on his lips.
Later, Henry chances upon Alice, swaying gently on a swing in the park. She inquiries about his work, prompting him to embark on a discourse on the intricacies of quantum physics. He elucidates how an object can occupy two places simultaneously or even possess two hues at once, a concept both fascinating and baffling.
Jo queries Magnus if she appears altered, and he concedes that she does. Henry happens by, depositing Alice safely and expressing gratitude to Jo for retrieving the CAL. He cautions her to be vigilant amidst the maze of bureaucratic players. Shortly after, Jo embarks on a stroll with her fellow crew members, all grappling with the implausibility of her claim. They visit Paul's grave, laying flowers in his memory. As Jo stands alone, she experiences a fleeting vision of Paul, standing before her, reciting a snippet of poetry.
At the conclusion of the meeting, Jo retracts her assertion regarding the space suit, finally bringing closure to the matter. The astronauts are now free to embark on their journey home. Jo is elated to be reunited with familiar surroundings, yet something seems amiss. She recalls having owned a red car, yet the one parked before her is a dazzling blue.
Irena makes an appearance at Henry's abode, and they share a bottle of wine. Irena reveals a harrowing truth - she is battling stage four lymphoma, her life slowly ebbing away. This, she declares, will be their final rendezvous. They engage in a slow dance, the music swelling as they sway to the rhythm. Meanwhile, on the ship, Bud approaches the debate host and demands a walk. The host punctures Bud's narrative with skeptical inquiries, his experience as a senior police officer lending credence to his skepticism. Suddenly, Bud pleads for help, confessing gaps in his memory, baffled as to how his colleagues perished while he adhered to protocol during the Apollo mission. He lays the blame on Henry, a name unknown to the host. As the host continues to taunt Bud, Bud's patience snaps, seizing the host and thrusting him overboard.
Back in his hotel room, Henry's eyes widen in horror as the image of Irena transforms into a corpse. In the present moment, Alice confides in Jo her suspicions, doubting the authenticity of the other cabin. She shares anecdotes of individuals who've traversed the cosmos and witnessed bizarre phenomena. Jo corrects Alice, clarifying that she is not her biological daughter. Alice, perplexed, inquiries about the whereabouts of her birth mother, leaving the episode of "Constellation" on a tantalizing cliffhanger.
