Good intentions, bad guy.
Elijah Price comes into the story as a baby, born with all his limbs broken. The scene of his birth is unusual in itself- it is shot entirely from a mirror. Already, his character is foreshadowed to be abnormal.
The hero, David Dunn, is the sole survivor of a horrific train accident. After attending a memorial to the other passengers, he walks to his car and finds a card that asks him how often he has been sick. He eventually meets the card's sender, Elijah Price, an eccentric comic-book collector. Price pursues his lifelong theory: there are those among us who simply don't get hurt, those who are unbreakable. He himself has a birth-defect which makes his bones break easily. He claims that if there is someone like him, there must also be someone "on the opposite end of the spectrum".
Throughout the movie, he aids Dunn in self-discovery. The ending is a shock to most of the audience, when they find that Dunn is truly a comic-book type hero. In the final scene, they shake hands and everyone can see what Price was all along. He caused the train accident, among other tragedies, only to prove his theory. Final words: "They called me Mr. Glass."
Price is arrested for terrorism, and it can only be assumed that Dunn continues his acts of heroism.