Transplant

Languishing in prison, House receives a visit from Foreman who's now Dean of Medicine at Princeton Plainsboro, after Cuddy's departure. Foreman has arranged conditional parole for him to come back to work at the hospital and deal with a particularly difficult case. But, if he breaks any rules he's back in prison.

House agrees and is given a small dark office and a smart yet timid assistant, Dr Chi Park, who's been paired with him because she's punched her boss after being groped. House is introduced to the 'patient' - a pair of lungs that are being prepared for transplant into one of Wilson's patients. They're not functioning properly and that's where House comes in. Wilson, however, wants nothing to do with House. As far as he's concerned, they are friends no longer.

The lungs belonged to a young man who's been killed in a motorcycle accident and House is determined to check out his home environment. Breaking his parole conditions, he takes Park with him to the young man's house and searches his room. He discovers that he'd been having headaches, suggesting a brain tumour, though after the police deliver House back to the hospital, this is quickly disproved. He then wants to check the donors who'd provided plasma to the man and a variety of possible causes for the lung problem arise and are soon dismissed.

Ideas are running out and the lungs are starting to fail. Then, House notices a nurse blowing out candles on a birthday cake and suddenly understands. The young man had inhaled a lot of cigar smoke at a poker game the night of the crash and it had been too much for his lungs. House's treatment is successful and Wilson's patient receives the lung transplant just in time to save her life.

As a reward, Foreman gives House half his old office back, though Wilson walks straight in and punches him to the floor... then asks him to dinner. It seems he's decided to be friends again.