Clark tells Lana his secret and proposes, Jonathon wins the election, Lana has a row with Lex and as he drives after her to appologise, Lana's car is hit by a bus and totalled, she is killed.
Clark goes to Jor El and asks him to save her, Jor El says that Clark can live the day over and make a different choice, but there must be a balance.
Clark starts the day over again and doesnt tell Lana or propose, they end up breaking up, she still argues with Lex, but Clark is able to stop the bus hitting her.
Johnathon wins the election, then has a fight with Lionel, but after throwing a couple of punches starts to have a fatal heart attack, which conviently doesnt let him die until Martha and Clark arrive back at the farm to see him collaps in their arms.
Episode ends with a slow mo funeral in the snow, and no, Johnathon wont be coming back to life.