When he was young, Wilson would slip into the living room during his father's faculty parties and listen to the physicists argue interpretations of quantum mechanics. His father was a Copenhagen man -- he still counts meeting Niels Bohr as one of the greatest moments of his life -- but Wilson always rooted for the many-worlds interpretation. He didn't understand wave function collapse or quantum decoherence, but the idea of an infinite number of universes existing in parallel, each one created by the differing outcomes of every event or choice, fascinated him.

Even now, it comforts him to believe that a universe exists where he found the right words for his brother, where Michael chose to stay and accept his help instead of striking out and turning away. In another universe, House's infarction was diagnosed quickly and correctly and they still go running three mornings a week.

The night Amber dies, Wilson lies awake, her last note to him clutched in his hand, and tries to think himself into another universe. A trail of choices leads back to the last moment he was happy, birthing a multiplicity of universes infinitely preferable to the one he exists in now.

He blinks and House calls Wilson's cell phone instead of their home number. Wilson grumbles and tells him he's a pathetic drunk, but he makes sure the duty nurse has his contact information and drives to the bar. He's still on-call, so he sips a coffee while House bitches his way through another two scotches. House's mood slowly shifts and they're both laughing when Wilson is paged back to the hospital. There's been a bad accident, dozens injured, and all hands are needed on deck. House is too wasted to be of any use, so Wilson pays his tab and pours him into a taxi. He calls Amber to let her know he'll be late and she says she'll be waiting for him. She is.

He blinks again and Amber sneezes in the bar and fishes for the anti-virals, claiming she has the flu. House tells her she's trying too hard to be like him and knocks the bottle out of her hand, scattering the pills on the floor. When she reaches for one, he crushes it with his cane and tells her she's an idiot for thinking they'll work. She tells him he's a possessive bastard who can't stand to share anything and the bartender throws them both out before they start actually throwing punches. But getting thrown out of a bar is a badge of honour in House's book and Amber is now his partner in crime, not an annoying adversary, so he clambers compliantly into her car. On the way back to his apartment they pass an accident scene, but they're in the middle of negotiating custody rules while she's away at a conference and they don't stop.

He blinks a third time and House and Amber are on the bus, but someone else has taken the seat across from House, so Amber sits in front of him. She sees the garbage truck approaching in time to brace for the initial impact, though she can't hold on and House can't hold onto her when the bus flips on its side. The metal bar still pierces her thigh, but her kidneys aren't damaged and the amantadine filters safely through her bloodstream. House stays conscious long enough to tie a tourniquet around her leg and tell the paramedics to bring them both to Princeton-Plainsboro. But the injury to muscles and nerves and bone is extensive. She is in rehab for weeks, and she resents being dependent on Wilson, and gradually she starts to resent him as well. When she is back on her feet and walking with only the slightest trace of a limp, she takes a job in Phoenix and doesn't ask Wilson to move with her. He never sees her again.

But she is alive. Somewhere.