Ryan faces a life-threatening mission but decides to donate one of his kidneys to his wife, Vanessa, despite the risks. He reflects on sacrificing his astronaut dreams and dedicating himself to her for three years while hiding secrets. Vanessa had once asked for a marriage, and Ryan recalls her love as he prepares for the transplant. Meanwhile, Vanessa feels neglected as Ryan misses their third anniversary again. As Ryan commits to this final act of love, the episode ends with a tense moment hinting at the uncertain outcome of the surgery and their strained relationship.