Joseph comes to see her in the hospital and the team realizes that he's not just a "friend" but is probably Natalie's boyfriend. She denies ever having sex with him, but admits they are very close.
As Andres appears to be stable, Robert Chase suggests she go home to get a good night's sleep. However, when she returns the next morning, Andres has left the hospital and is missing. She's furious, but House realizes she's guilty about finally having sex with Joseph rather than the hospital's mistake. Although she wants to go looking for Andres, House tells her that they need her there so they can question her about where he might be. Andres would have known it was Saturday and Natalie remembers that on Saturdays, he used to go to a nearby soccer field to coach young soccer players.
Andres is found cold and unconscious at the soccer field. They slowly start to revive him, but Andres has stopped speaking English and can't remember who she is. She breaks down and says she can't care for him any more because it's just too hard.
However, Andres is finally diagnosed with Reye's syndrome and, as he starts to improve, he starts to speak English and recognize Natalie. She decides to stay with him.