The second longest day of Jack Bauer's life finally winds down. And it has been quite an eventful 24 hours, what with the nuclear threat to Los Angeles; the bombing of CTU; duplicitous dames Marie Warner and Sherry Palmer; cringe-inducing tortures; a rapidly climbing body count---and a presidential coup. Tonight's finale finds an unexpected alliance formed in a last-ditch effort to take down mastermind Peter Kingsley (Tobin Bell), while new information about the villain has an impact on Tony and Michelle, and the race to halt the ill-conceived air strikes in the Middle East.

Sherry agrees to wear a wire to help Jack get the evidence from Peter Kingsley. Mike calls Ryan at CTU and tells him to give Jack his full support after thinking about all the civilian casualties. Ryan lets Tony and Michelle go. Kate and Kim go to CTU and they find out that Kate's father and Marie is there. Marie won't say anything until her father leaves then she tells Kate that she isn't safe out there. They get the recordings from Kingsley, but Kingsley thinks that Sherry really doesn't have the hacker, so he orders his sniper on the roof to take her out. The sniper isn't there though, because Jack took him out and starts shooting Kingsley's guys. There is a big shootout ending with Jack getting heart problems and Kingsley coming up to him with a gun. When he is about to shoot Jack a SWAT team that Ryan from CTU ordered to go out there shoots Kingsley. Palmer is put back in as President and the war is called off. Palmer lets everyone keep their job except for Mike, who he relieves of his duties. The guy on the boat finds out the war is cancelled from another guy that looks to be at an outside restaurant. The guy on the boat said they will have to do it another way so then he calls someone and tells them to go ahead. Kim and Kate meet up with Jack on a stretcher and Kim says she will take care of Jack and she loves him. Ryan puts Tony back in charge of CTU. The President is holding a press conference when a girl tries to get his attention. She shakes his hand then goes behind a wall and pulls off a piece of plastic off her hand. The President is about to get in his limo when he looks at his hand and it looks like it has been burnt with acid. He collapses on the ground to end the show.

yep

killed, revived, jacked up for two hours, then is fighting possible heart problems...

How do they get Prescott (the now president) out of president to it now being Palmer again.

Prescott relinquishes his job as President and gives it back to Palmer once he finds out the evidence is real and the tapes were fake.

the chick who gives Palmer the poison is none other then Mandy, from season 1. She was the one who bombed the plane in the first episode and had that brief lesbian scene a few episodes later.