Episode 6 of Constellation opens with a thrilling scene aboard the ISS. Paul, engrossed in his work on the CAL, is interrupted by the sound of Jo's urgent conversation with Alice on the phone. Suddenly, Paul plugs in the CAL, and the commotion erupts, sending Jo crashing into a glass panel and suffering severe injuries. Paul rushes to her side, desperation etched on his face.
Meanwhile, at school, Magnus and Alice receive shocking news that leaves them stunned. Back on the ISS, Paul frantically searches for the CAL, but it's nowhere to be found. As the other crew members depart, Paul instructs them to inform Henry about the missing CAL, but they seem oblivious to his frantic pleas.
Later, as Paul lies beside Jo's lifeless body, he hallucinates that she is still breathing. Down on Earth, Magnus discovers Alice hiding in a cupboard, refusing to come out. Her necklace hangs tantalizingly on the knob outside, and she taps her foot, creating a rhythmic noise. Suddenly, she spots Jo approaching with a flashlight, but the vision fades into nothingness.
In space, Paul is haunted by strange noises that gradually transform into Jo's voice. When he establishes contact with Houston, he suggests leaving Jo's body behind due to the extent of her injuries. He carries her to a secluded part of the ISS, where, to his amazement, Jo suddenly grasps his hand, revealing that she is, in fact, alive.
Meanwhile, Alice is playing with Wendy, who excitedly shares that her father is coming home. Magnus arrives and breaks the news to Alice that they're leaving Jo behind in space. Paul faces a similar malfunction on his Soyuz, but to his amazement, the issue mysteriously resolves itself, despite requiring the assistance of two crew members.
As he turns back, a silhouette emerges within the ISS, casting a mysterious shadow. Paul's return is greeted with great jubilation, but when he embraces his wife, he calls her Frida instead of Erica, a startling revelation that hints at deeper, unseen changes within him.
Magnus valiantly attempted to comfort Alice amidst her anguish over her mother's abandonment in the vastness of space, but his efforts were futile. Meanwhile, Paul solemnly journeyed to lay flowers on Jo's gravesite, where he beheld a haunting vision of Jo herself gracefully placing blossoms there.
Later, gathered with the others, Paul struggled to explain the extent of Jo's injuries to Alice, but his graphic account was too much to bear, prompting Magnus to escort Alice away in a hasty departure. Alice wandered aimlessly, her thoughts clouded, until she spied Henry Caldera waving through a window, a beacon of familiarity in her turmoil. She found herself in a parking lot, where in a moment of emotional distress, she stomped on her cherished rabbit. Wendy tried to intervene, but Alice's anger was too intense.
During the meeting with space personnel, Paul was the lone voice remembering the CAL, while Houston steadfastly refused to acknowledge their role in leaving Jo stranded. At home, Alice lashed out at inanimate objects, venting her frustration. Suddenly, the tinkling of a piano filled the air, a haunting melody that seemed to echo her mother's absence. Magnus's therapist suggested that Alice needed a ritual to help her cope with her mother's passing, a ceremony that would bring closure.
Meanwhile, Paul immersed himself in videos of the Apollo 18 mission, searching for clues. He heard a familiar static noise, reminiscent of what he had heard on the ISS. Determined to find Henry Caldera, he discovered that there was only a Bus Caldera. Michaela informed him that Apollo 18 had been a disastrous mission, and she had no knowledge of Bud's whereabouts.
Later, Paul sat at breakfast with his family, but his mind was still fixated on Jo, frustrating his wife. As the day of the funeral dawned, Alice hid in a cupboard, refusing to face the reality of her mother's absence. Paul and his family arrived, but his emotions were raw, his anger boiling over as he railed against the injustice of leaving his friend in the void of space.
At the funeral, Paul's anger flared again as he chastised Wendy for not speaking to Alice. Wendy, enraged, pulled Alice aside and revealed that her father clung to the hope that she might still be alive. At that moment, Alice's world shifted, as she saw another Alice clad in pajamas and, shockingly, a vision of Jo. She screamed for her mother, her heart breaking all over again.
Magnus gently guided Alice away, suggesting they seek solace in solitude. Alice insisted on visiting her mother's cabin, a sanctuary that held memories of happier times. As they journeyed to the cabin, a snowstorm descended, adding to their isolation. Alice, determined, insisted on walking, her resolve hardening with each step.
Meanwhile, Erica awoke to find Paul missing. Enlisting Michaela's help, she learned that Paul needed to be taken to a rehabilitation clinic. Far away in California, Paul arrived at Bud Caldera's house, searching for answers that might lead him to peace.
Inside the cabin, Magnus and Alice found solace in each other's presence. Magnus broke down, sharing his own pain over the loss of his wife, and together they realized they must forge a new path forward, one step at a time.
Paul confronts Bud in a tense encounter. Inside Bud's abode, Paul stumbles upon clips depicting the tragic Apollo 18 accident. However, Paul's recollection differs greatly from Bud's. In Paul's narrative, every crew member returned home unscathed, safe and secure. But in Bud's version, the tale is much darker, revealing that two brave men lost their lives in the disaster.
The contrasting accounts spark a heated debate between the two, their voices rising in anger. The argument escalates rapidly, and Bud, enraged, reaches for a gun hidden within the shadows.
Meanwhile, in the secluded cabin, Alice stirs from her slumber, startled by the sound of a car approaching. Her eyes widen as she watches the vehicle roll to a halt outside. Out steps Jo, emerging from the vehicle at the climax of the sixth episode of Constellation, adding yet another layer of mystery and suspense to the already tense situation.
