Contains spoilers for this episode.
Cliff and David spend a long space mission physically aboard a ship while using artificial replicas to live with their families on Earth. Their arrangement gives them domestic lives between duties in space. David's family is attacked by a cult hostile to the replicas. Forced to watch their murders before his own replica is destroyed, he is left isolated aboard the ship with no body through which to return home.
Concerned for his partner, Cliff allows David to borrow his replica. Lana welcomes the grieving visitor, and David begins painting at the family home during arranged visits. His gratitude develops into desire, creating an intimacy Lana has missed with her husband. When David makes an advance, she rejects him. Cliff discovers drawings of Lana, confronts David and hears enough to make him fear that generosity has become an invasion of his marriage.
Cliff forbids further visits and tells David that Lana wants him gone. David then creates a false emergency that sends Cliff outside the spacecraft, leaving his link available. When Cliff returns to Earth, he finds blood throughout the house and collapses at the sight of his murdered family. Back aboard, David silently pushes out a chair for him. Both men still depend on each other to operate the ship, but the shared loss David has imposed leaves their remaining years together beyond any simple reconciliation.