Simone, a female-identifying android, is part of a scientific team sent ahead of the first colony to return to Earth, which is finally habitable again after centuries of radiation recovery. She mostly finds her human crewmates irritating, and the most irritating by far is Dr. Lucy Zhong, who slowly becomes Simone's best friend, more important to her than anyone else has ever been.
When Lucy is fatally injured, she kisses Simone during her last moments of consciousness. Only then does Simone realize they may be more than friends. To save Lucy, Simone places her in the last functioning cryo-pod, even though this means sacrificing another crewmember. Simone's programming should not permit that kind of choice, but if this is a malfunction, Simone doesn't care as long as it saves Lucy.
When the colony ship arrives, Lucy is revived, and discovers it's her turn to play rescuer, as Simone has been slated for deactivation. Does the android's "malfunction" mean she returns Lucy's feelings? If Lucy can't save her beloved Simone, she'll never find out.