Sam and Dean go to Missouri to track down a shapeshifter that kills its victims by taking on the shape of their loved ones.

When the Impala breaks down in Louisiana the boys learn the town has been suffering from a series of demonic omens and accidents. But in each incident, no one is actually hurt or maimed.

In Afghanistan, Jake, a foot soldier was always being made fun of. However, when the troops faced destruction, he exercised his superpower to help his fellow soldiers and evacuated them from the battlefield. Meanwhile, Sam sees another premonition.

Sam and Dean investigate a series of strange accidents on a mountain road. They come across Molly who insists she and her husband just crashed their car, problem is her husband and the car are missing

Following what Sam has seen as a vision, Sam and Dean visit their childhood home in Lawrence Kansas. Sam and Dean discover an unseen force is terrorizing the current residents of their house, a mother and her two children.

While driving through New Orleans, the Winchester boys are stopped by the police and arrested. It seems there have been a series of accidents caused by an Impala -- and the police think they're the perps!

Sam and Dean investigate a serial murder case and learn that since the 1960's similar murders have been repeated every 15 years. They meet Dr. Richard, the widower and Richard's young and beautiful second wife, Michelle. More attacks occur.

A spate of wild dog attacks draws Sam and Dean's attention. Sam and Dean suspect that it has something to do with a werewolf. They visit Madison, a friend of one of the victims thinking she may be the next victim.

Sam's premonitions are getting stronger. After a man dies Sam and Dean visit the family and meet Max, the man's son. Though Max claims his family was happy Sam and Dean have their doubts.

In a small town in Colorado, Sam and Dean investigate a series of cattle mutilations, the beasts have been drained of their blood. They run across Jason, a hunter who specializes in vampires, but wonder why he's in town.

Sam and Dean reunite with their old friend Bobby. As they track down clues to John's whereabouts they find out that a buddy from John's Marine days has been murdered in a strange fashion.

Lady luck? Not really. Sam and Dean stop by Las Vegas for a little fun and relaxation -- plus to try their hand at the tables. But bad luck soon befalls Dean, and there is some strange guy following him.

Drawn to a town lighting up with demonic signs, John meets Lily, a girl whose mother died in a fire years ago much like the one that killed Mary. John learns Lily has a fatal gift; if she touches someone they die.

Sam and Dean are finally reunited with their father. But happy endings aren't in their family's future. John tells them about "The Colt", a gun that can kill anything. And right now it's in the wrong hands.

Sam, Dean and John were badly hurt in the battle with the demons and are taken to the hospital. Sam and John recover, but Dean remains unconscious. Dean's soul wanders in the hospital as a ghost and meets a Reaper.

Dean visited Missouri because he struggled with the true meaning of John's last words... "Save Sam, or kill him". Some old photos remind Dean of Mrs. Lyle, who was Sam's teacher. He remembers how he and his father saved Sam, despite what his future held.

Going back in time we revisit the first time Sam meets Jessica, and learn the secret she shared with her childhood friends. Now that secret is coming back to kill them. Can Sam save the girls by himself?

With their hands on the Colt, everything else should be easy, right? Wrong. John gets trapped by Terry, an evil demon, and the boys have no choice other than to run.

Dean wakes up one day in a totally different world. His mother Mary is alive, he is married to a fine woman, and Sam is engaged to Jessica. Dean soon realizes he's been captured by a Djinn, who is slowly bleeding him dry.

An architect commits suicide. Sam and Dean followed a clue that some other successful people had died in the similar way as the architect within a year, and find out that those people had all bargained with "the crossroad demon".

Demonic omens are becoming more and more frequent. Sam wakes up to find himself in a ghost town with other psychics: Lily, Jake, Andy, Eva. They soon realize that they are similar; they all have powers.

In a surprise ending, Jake stabs Sam and kills him. Devastated by grief, Dean makes a deal with the crossroad demon to bring Sam back; as a trade-off, Dean gets one more year to live, after that -- his soul is toast.