Adam Sandler plays a former New York firefighter who lost his whole firehouse on 9/11. This movie is set in the leadup to the tenth anniversary observances.
This is the opening big joke of the movie, he’s at a bar, chatting somebody up, she’s impressed until he tells her that, he lost his whole house, she says “You lost all your friends?” And Sandler’s like, no, the firehouse got lost. Not burned down or anything, lost! Wait’ll you find out how! Pretty soon, she’s throwing drinks in his face, other people are, he’s all “I WISH I’D NEVAH EVEN HOID O’ 9/11!”
Anyway, she hits him over the head and he stumbles out into the street, is hit by a cab full of Arab stereotypes and wakes up in another world. And here’s the twist: you think it’s going to be a world where 9/11 never happened, but no. He’s in a world where something awesome happened on 9/11, and everybody’s getting ready to par-tay.
Plus, you have to have some random wacky thing to get by in this world you’d never have here, like an implant in your butt or vaginas in your ears, so Sandler is on the run, constantly being offended by posters and songs and ads and various propaganda of a “GOD BLESS 9/11” nature. There is a girl, but she learns to look beyond the lack of vagina ears.
Anyway, the firehouse fell into the other dimension, duh.
And a 9/11 happens at the end that unites both worlds.