Joseph first appears when Robert Chase and Chi Park are doing a procedure on Andres. Park explains that only family are allowed in the room during procedures. Natalie says he is a close friend, but Park is firm and Natalie and Joseph eventually leave for a break while the doctors finish. Chase tells Park she was being insensitive and thinks Natalie and Joseph may be lovers.
Later on, Natalie agrees to take the night off from taking care of Andres, but when she returns the next morning, Andres is missing. She goes to leave but House realizes she isn't angry, but guilty and that part of the guilt is because he thinks she finally slept with Joseph for the first time. She eventually helps the doctors realize that Andres is probably confused and is at a nearby soccer field.