House conveniently finds Nick's dad by himself outside Abby's room. House asks him if he travels often, specifically to the Middle East. Dad says he does for work. House says he exposed Abby to a parasite, which Abby's immune system was then able to kill off, leaving a tiny microscopic shell that didn't show up on their scans or tests but did set off an allergic reaction, a.k.a. Cerebellar Schistosomiasis Hypersensitivity Allergy. The good news is it's curable. The bad news is that Abby could only get the parasite from Nick's dad by having sex with him. OOPS! Another sexual encounter ends in serious health problems on this show. House says that if Nick's dad doesn't tell him the truth that he slept with Abby, then she will die. Unfortunately for Nick's dad, both Nick and Abby's mom choose this moment to check out what's going on in the hallway. House stands back to enjoy the moment as Nick's dad admits that one time, when Nick and Abby were broken up, Abby came to Nick's dad upset and crying and Nick's dad was drunk, so that makes it all okay. Nick takes off, leaving Abby's mom standing there looking homicidal. As she should. Go ahead and kill him, Abby's mom. PPTH Security won't stop you, because they're terrible.
House arrives home to find an apartment full of furniture again. He immediately knows that Wilson used a decorator and threatens to return the furniture so that Wilson can learn a lesson about retail therapy or something. But then he spots something covered in a sheet by the window. He removes the sheet to find an organ. It's the kind of organ used to play Dracula's theme, which House immediately does. He smiles and says that the decorator didn't pick the organ out, which means that Wilson did, in fact, buy a piece of furniture. And what it says about Wilson is that he is a pushover who lets his friend walk all over him and take advantage of his doormat-ness. House then proceeds to play "A Whiter Shade of Pale," because it's either that or the wedding march. Also, it leads nicely into another montage, as Abby gets brain surgery to remove that microscopic parasite shell that didn't show up on any scans but they still somehow knew where it was. Nick and his dad talk, but it doesn't seem to be going very well, as Nick leaves in a huff. Which makes sense, since I don't know what Nick's dad can really say or do to make any of this better.