I think that jack might die at the end of season 3.
The others are about to let him go however are going to kill kate.
Jack becomes the hero again and saves kate however dies.Just before Jack dies he kills Ben
That when the season 3 ends

At the start of season 4 we see where micheal and walt are.
They are in a town where penny (demond's girlfriend) is.
At the island kate is saved by sayid and locke and then when they are about to go to the beach the moster appears and then finish.










O yeah i forgot the monster kills every one the losties and the others.









Did i tell u i am the monsters

Ha ha ha