If You Were the Last

In their living room, Adam and Jane debate whether NASA would spend billions to save a single astronaut stranded on Mars, invoking The Martian as a reference point. The discussion widens as Saturn looms outside the window, underscoring the vastness of space. Benson, their inanimate confidant, becomes part of the argument as Adam hints Jane has gone too far in her optimism while another astronaut's remains remind them of the stakes.

The crew settles into their third year in space with a strict routine: joint exercise, daily tasks, and maintenance. Jane handles spacecraft maintenance and tries to reestablish comms and navigation, while Adam tends to the plants, chickens, and a goat. They cope by sharing chess, films, and music to keep their minds anchored.

After a cardio routine, Jane scolds Adam for masturbating in the greenhouse, and he suggests they have sex to relieve stress. She laughs at the notion, yet Adam persists, arguing it would be devoid of romantic implications. Their tension marks a turning point in how they relate beyond companionship.

They watch Alien, and the fear unsettles Adam, who crawls into Jane's bunk. Naked, Jane wakes and suggests cuddling as a mental health boost. She lists the third reason not to have sex—Space Babies—and they realize condoms aren’t provided; Adam jokes about possible radiation-induced sterility before Jane leaves in disgust.

The two vent to Benson about each other, treating the inanimate confidant as an audience. Jane admits she has adapted four power drills into dildos and has contemplated sex with Adam, while Adam admits he finds her attractive. He insists her reasons against sex are foolish given their isolation and lack of rescue.

They watch messages from their spouses—Adam hoping Savannah has waited for him, Jane sensing Tom would have loved being there. When Jane loses her music, Adam steadies her, and their bond deepens as they endure the monotonous days together. When the space goat dies, they lose fresh milk but gain 50 meals, and Jane bakes homemade pop tarts for Adam to cheer him up.

The day after deciding to do everything except sex, they regain navigational control and realize their return will take three weeks. They abandon the plan to abstain and begin having sex frequently as the countdown back to Earth resumes. The intimacy deepens even as the stakes remain high, highlighting their dependence on each other.

They reflect on what they miss most: Jane longs for exploration and music, while Adam misses his wife's hugs. He wishes she would stay his best friend, but Jane resists the idea of maintaining a platonic bond. The rift signals that their bond has evolved beyond friendship, driven by shared survival and desire.

At a Earth press conference, they are asked about Benson; Jane claims she died in her sleep, but a flashback reveals she axed him to save Adam when she went crazy. Savannah suddenly appears, kisses Adam, and leads him away, prompting a battery of medical tests. The exposure forces them to confront their actions in the public eye.

In debriefings on Earth, Adam talks about experiments mixing blueberries with marijuana, while Jane recounts Benson turning violent and demonstrates the drilled implements. Their spouses finalize discharge papers, and they say their goodbyes, with Adam asking to stay in contact and Jane refusing. The emotional fallout underscores the fragility of their relationships back home.

Returning to Savannah's world, Adam feels invisible as he keeps shuttle chickens in the house, which bother Savannah. Jane and Tom share a quiet conversation in their bed, and Jane admits that dancing with Adam was her favorite part of space life. Tom resists at first but recalls Jane's long confinement and softens.

On a run, Jane hears a song and her feelings for Adam flood back. Back home, she discovers Tom had been seeing Amber and insists he contact her. She then confesses her and Adam's ongoing sexual relationship, shattering any remaining illusion of normal family life.

Nine days after their return, at a White House dinner, Jane tells Adam and Savannah that she split with Tom. The President asks them to demonstrate their dancing skills, revealing their chemistry to the public. Savannah sees the undeniable connection, and both Adam and Savannah decide to part ways.

In a final turn of hope, Adam goes to Jane and declares they are meant for each other. They decide to take a trip away together, leaving their old lives behind to pursue a future together.