Who's Your Daddy? (House)

"Who's Your Daddy?" is the twenty-third episode of the second season of House and the forty-fifth episode overall. The title is in reference to two separate stories in the episode.

The episode's beginning starts with a Hurricane Katrina victim Leona, (Aasha Davis) who hallucinates water gushing into a plane she was on. After the hallucination, the scene changes to House, pacing about in his apartment. It's apparent that his leg pain is worse than usual. As he is about to inject himself with morphine, he receives a message from Cuddy, calling about the patient. House accepts the case and meets up with the father, Dylan Crandall (D. B. Sweeney), who is an old friend of House's. House is skeptical that Dylan is the father, and tells him that she might just be scamming him.

The team and House ponder what sparked the hallucination, but Leona's heart is perfectly fine in the hospital. Foreman suggests arrhythmia and House decides to proceed in inducing arrhythmia by sending electric pulses to her heart. After getting consent from Dylan, they start the procedure. However, after a few pulses, she gets a heart attack, but no hallucinations. They decide to send another pulse, this time to the right atrium. This pulse starts the hallucination. They freeze the damaged muscle which is near the coronary sinus. As the muscle has been destroyed, House says 'She'll be fine by breakfast.'

Leona gets out of bed after hearing a woman call out for water. As she pulls back the curtain to the other bed, she hallucinates her mother, covered in dirt and weeds, leaking water. As the team wondered what triggered the second hallucination, House comments that it may not be a hallucination but an atypical seizure. He then walks out for a short time, which is explained by Cameron who notices his leg hurts. House then says it might be a flashback post-traumatic stress syndrome. When Cameron asks why he thinks it is not a hallucination, he says her heart problem they fixed would then just be a giant coincidence and then walks out again, only to come back and say there is a possibility some sort of pain is causing her hallucinations. He then leaves again to test try his theory out. During the test, his theory is proven right as Leona hallucinates House's face melting. House says she needs a bone marrow transplant and while they're looking for a donor, Dylan goes into House's office and says he can be the donor as he is her father. He tells House to test his marrow to see if he's a match, but also tells him not to run the paternity test because Dylan will "lose either way".