This suspense thriller unfolds as the audience is introduced to David Dunn. Not only is he the sole survivor of a horrific train-crash that killed 131 people he doesn't have a scratch on him. Elijah Price is an obscure character who approaches Dunn with a seemingly far fetched theory behind it all.
Security Guard David Dunn miraculously survives a catastrophic train crash outside Philadelphia. Not only is he the sole survivor out of 132 passengers, he also is completely unharmed. A little later, comic book specialist Elijah Price contacts him to confront David with an incredible theory: Elijah, who has been nicknamed "Mr. Glass" due to his more than fragile bones, thinks that David has got all which he himself lacks. The two of them "seem to be linked by a curve, but sitting on opposite ends". First, David does not believe the strange man, but every single thing he had said proves to be true: David has never ever been hurt or sick in his life, his physical strength is larger than normal and he has a skill which others don't. Slowly, David begins to discover the shocking truth behind Mr. Price's assumptions. But after all, David's fate is not only to find his real place in the world. It also is about proving Elijah's theory of his own existence.
David Dunn's marriage is crumbling, and he's thinking of moving to New York. Then when he's coming home from a job interview, his train derails and he is the only survivor. More than that, he doesn't have a scratch on him. David is contacted by Elijah Price, who runs a comic book art gallery and suffers from a genetic condition that makes his bones very easy to break. Elijah has been a comic book fan all his life, and has developed a theory that they are what remains of an ancient system of storytelling, and the superheroes they are about are based on real people. Elijah believes David may be one of these people. He has hardly ever been injured or sick, and he has tremendous strength, plus an uncanny ability to tell if someone is about to or has done something bad. David doesn't know what to think about the theory, or Elijah himself. However, events soon conspire to convince him he may be a superhero after all.
A security guard named David Dunn is coming home from work, when the train he is on is suddenly derailed, the train crashes, and he is the sole survivor, out of 132 people. Without a scratch on his body. Soon he is contacted by comic-book store owner Elijah Price whose bones are easily breakable, who claims David is a superhero.
A man learns something extraordinary about himself after a devastating accident.
- The film opens as we see a baby being born in west Philadelphia. This is Elijah Price (Samuel L. Jackson). Elijah is so brittle that he is born with broken arms and legs. As he grows older, he is taunted at school and called Mr. Glass by his classmates since he is so fragile. As an adult, he runs a successful high priced comic book art gallery specializing in original drawings of super heroes.
David Dunn (Bruce Willis) is a security guard at the local college stadium. His marriage is crumbling and in fact, his wife, Audrey Dunn (Robin Wright Penn), sleeps downstairs in their son's room, and David sleeps upstairs with his son (Spencer Treat Clark).
On his way back home from a job interview in New York, David's train malfunctions and derails, killing everyone on board except David. He doesn't even have a scratch. After the memorial service for the crash victims, David finds a note on his windshield. It's from a store named "Limited Edition" (Elijah's store) and the note asks, "How many days of your life have you been sick?"
David asks his boss and his wife but no one can ever remember him being sick. David takes his son to "Limited Edition" where he meets Elijah.
Elijah explains his theory to David... If Elijah can be born with brittle bones and very easily hurt, shouldn't there be someone the exact opposite? Elijah has researched every disaster to find a sole survivor without a scratch but has had no luck. After years of searching, he finally has found one in David Dunn.
David thinks it's interesting but really just thinks Elijah is nuts. Back at the stadium, David gets a call that there is someone there trying to sneak in and asking for David. It's Elijah and he starts explaining his comic book theories to David. Theories about everyday men being super heroes, having powers they haven't yet realized and so on. David bumps into a guy in line and tells the security at the end of the line to start frisking people. They watch as the guy David bumped in to, sees everyone being frisked and leaves the line. Elijah asks David what that was all about and David tells him that when he bumped him, he had an image of a certain kind of handgun.
David goes back to work but Elijah follows the guy David bumped into. They go down a long flight of stairs, Elijah falls shattering his leg and breaking several other bones but the last thing he sees is the man's handgun, just as David described it. Elijah was right, David does have some kind of special gift.
Back at home, David is working out in the basement with his weight set. His son believed everything Elijah said about David being a hero with a special gift. David still doesn't believe. David asks his son to take some weight off but without him knowing, he puts more weight on. David lifts 250 lbs, the most he's ever done. His son continues putting on more weight until David is now up to 350lbs. He has had all this strength all along that he never knew.
Elijah needs his leg rehabbed and his nurse is Audrey, David's wife. Elijah asks her questions about her and David and she explains to him how when they were going out, David was a star football player but got in a car accident due to icy roads. David never played football again. It was because of that, that she and David were married. Had he continued to play, she knows they would have grown apart.
Back at work, David gets a call from his son's school that his son has been hurt. His son had hoped that some of David's super hero traits had rubbed off on him. He tried to protect someone that was being picked on and instead got hurt in the process. The school nurse remembers David from when he was at that same school. In fact, it was because of David that they have strict rules about the pool. It seems that David had been picked on near the pool when he was a student there. He fell in and was left in the pool to drown. He was found at the bottom of the pool but somehow survived.
David tells this story to Elijah, that in fact, David can get hurt. Elijah tells him that every super hero has a weakness. David's kryptonite is water. The water from the pool and the water from the icy roads.
David's wife decides that him surviving the train crash is a sign that maybe they should give their marriage another try. They go out on a "date" and he explains to her that he felt their marriage was over when he stopped waking her up after he had a bad dream.
The next night, David breaks into the train station and examines some of the wrecked trains. He starts recalling his own car crash from years earlier and remembers that he wasn't hurt at all. In fact, he had to use his superhuman strength to rescue Audrey from the flaming vehicle.
He goes to Elijah and tells him he is right, he has never been sick or injured in any way. Elijah tells him that it's no coincidence that David is in the security field. He needs to go to where people are and protect them.
It's a rainy day and David, wearing a hooded rain poncho heads to Penn station. Hundreds of people are passing by. Whenever someone bumps into David he has a vision of that person doing something evil. One is a jewel thief, another a rapist, but when the maintenance man bumps into him, David gets a horrible vision. The vision is of the man going to someone's home and killing the homeowner.
David, still wearing the poncho now looking more and more like a super hero's cape, follows the guy as he leaves work. The guy goes to a nice house in a nice neighborhood. David sneaks in the back and finds the dead homeowner inside. He goes upstairs and rescues two sisters tied up in their bathroom. He goes into another room and finds the mother tied up. The window is open and David looks out. When he turns back around, there is the maintenance worker who pushes David out the window. David lands on the backyard pool that has its winter cover on. Suddenly, the cover starts collapsing with David's weight and he gets all tangled up underwater with the cover. He is drowning again but the two sisters force a pole down to him and David grabs it and is saved.
David heads back upstairs and wrestles with the guy and finally kills him by breaking his neck.
The next scene is David back at home, hanging up his cape, er um.. poncho, and carrying his sleeping wife upstairs to their bed. She wakes up and asks him what is wrong. "I had a bad dream" he says.
In the morning while having breakfast, David slides the newspaper over to his son and holds a finger to his mouth to shush him. The headline tells of a mystery hero that saved the two girls. The picture is an artist's rendition of what the girls saw. It shows a superhero-like figure with a hood and cape. The boy looks up at his dad and David just smiles and nods.
David goes to Elijah's gallery where Elijah is having a huge gathering for a special show. He and David go to Elijah's back office so they can discuss what had happened. Elijah has been in a wheelchair since his fall. He is real proud of David and they shake hands.
Just like Christopher Walken in Stephen King's "The Dead Zone", while shaking hands, David has a vision of Elijah setting a building on fire, another vision of Elijah causing a plane crash and finally, a vision of Elijah exiting the driving compartment of David's train that crashed. David looks around Elijah's office and is horrified at what he sees. Newspaper clippings of hundreds of disasters from around the world. Elijah is the mastermind behind all these events and has staged them for his own selfish benefit.
Just like in the comics, every evil villian needs a worthy adversary and Elijah has finally found his.
David backs away in horror as Elijah, who in his wheelchair now looks more like Professor X of the X-men, proclaims...
"They call me Mr. Glass!"
Just before the final credits, a message appears that says that David contacted the authorities and Elijah is now in a mental institution.