Claim: Robert Chase worked under a fictional character.

Robert Chase , MBBS is a fictional character on the Fox medical drama House . He is portrayed by Jesse Spencer . His character was a part of the team of diagnosticians who worked under Gregory House until the end of the third season when House fires him . However , he resumed work at the hospital as a surgeon , and was re-hired by House in season 6 . Robert Chase is the longest-serving member of House 's staff . Chase has been attracted to Allison Cameron since the beginning of the show and embarks on a romantic relationship with her in `` Human Error . '' In `` Post Mortem , '' he left the Diagnostic Team after realizing he was in the same position as he was 10 years earlier , unlike all of the other former members of the team . However , in the series finale , he rejoins the hospital as the new Head of Diagnostic Medicine , replacing House , who is thought to have died .