Ever notice that every blockbuster movie has the same fundamental pieces? A hero, a journey, some conflicts to muck it all up, a reward, and the hero returning home and everybody applauding his or her swag? Yeah, scholar Joseph Campbell noticed first—in 1949. He wrote The Hero with a Thousand Faces, in which he outlined the 17 stages of a mythological hero's journey.

About half a century later, Christopher Vogler condensed those stages down to 12 in an attempt to show Hollywood how every story ever written should—and, uh, does—follow Campbell's pattern. We're working with those 12 stages, so take a look. (P.S. Want more? We have an entire Online Course devoted to the hero's journey.)

Ordinary World

Billy Costigan just wants to be a Massachusetts State Police officer. He goes through all the training that's asked of him, and he passes with flying colors. And all of that looks like it's going to go just fine. But we wouldn't have much of a movie if everything went as planned, right?

Call to Adventure

Despite his good grades and excellent performance on the police test, Billy gets dressed down by Special Investigations and basically told to his face that he'll never be a State Trooper. For starters, he comes from a long line of criminals. On top of that, Captain Queenan thinks that Billy is just trying to prove something to himself by being a cop. The kid has incredible scores on his SATs and could be whatever he wants.

But before letting him go, Queenan asks Billy if he wouldn't mind becoming an undercover agent for the police and moving back into his old neighborhood.

Refusal of the Call

At first, Billy doesn't think much of the offer for him to become an undercover cop, since it means that he's not going to become a regular cop. On top of that, he'll probably get cut loose once his work with Frank Costello's gang is over. He also doesn't like Sergeant Dignam getting in his face about what a rich jerk he apparently is. Nevertheless, he eventually agrees because he likes Captain Queenan and wants to do an act of service.

Meeting the Mentor

In some ways, this movie is a Tale of Two Mentors. On the cops' side, you have Captain Queenan, and on the criminals' side, you have Frank Costello. Queenan is the guy who wants to school Billy in all the arts of police deception, while Costello wants to teach Billy to go out and take whatever he wants from life. For the sake of clarity though, we're going to go ahead and say that Queenan is Billy's main mentor in this movie, since Frank is more of an antagonist.

Crossing the Threshold

Billy starts his life as an undercover cop by heading into jail for several months on an assault charge. He didn't actually commit the crime, but Captain Queenan has sent him into prison to help establish his street cred as a criminal, since everyone around town knows that Billy was in the cops for a while.

As soon as he gets out, Billy keeps establishing himself by moving back into his old neighborhood of Southie and doing drug deals with his cousin. Then he gets himself deep into gang activity by brutally beating up a couple of guys from the mafia. After that, there's really no going back, because now the mafia wants him dead.

Tests, Allies, Enemies

Over time, Billy makes friends with the folks in Frank Costello's criminal crew—but he's only pretending to be their friend to get to Costello. Meanwhile, his true allies are Captain Queenan and Sergeant Dignam, the only two people in the whole world who know that he is an undercover cop.

As time goes by, Billy decides that he can't take the stress of being undercover anymore, and he demands that Queenan and Dignam pull him out of the field. But Queenan convinces him to stick with it until the department has built a good case against Costello.

Approach to the Inmost Cave

Things get real when Costello sits Billy down one day and accuses him of being a rat for the police. Now Billy's only chance at survival is to double down and take a risk in order to throw Frank off his scent. He basically tells Frank that he'll kill him if he ever accuses him of being a rat again. Now Frank Costello could easily kill him for speaking to him this way, but he doesn't, and Billy's little gamble pays off.

Ordeal

Everything goes off the rails when Costello and Billy go to a drug deal that gets busted by the police. Billy barely has time to escape, while Frank and the rest of his crew are blown away by the police. On the bright side, Billy made it out of the whole thing alive, and it looks like his job is done, since everyone is dead. But on the other hand, Costello's rat in the police department will probably walk away from this whole thing a free man.

Reward (Seizing the Sword)

After Costello's whole gang has gone down, Billy heads into the police station to pick up his money and get his normal identity back. But there's still the unresolved question of what the police are going to do about the rat in their station. Little does Billy know that he's actually getting debriefed by the rat himself, Sergeant Colin Sullivan. He only realizes this when he sees an envelope from Costello's crew with "Citizens" written across it on Sullivan's desk. Then Billy disappears without a trace.

The Road Back

After ditching out of the police station, Billy sets a trap for Colin Sullivan, and Colin walks right into it. Billy arrests Colin, despite the fact that Colin has erased his name from the system, and no one has any clue that he's a cop. Unfortunately, there really is no final road back to normal life for Billy, because another crooked cop shows up and shoots him through the head before he can turn Colin in.

Resurrection

After getting a second chance at life, Colin Sullivan tries to act as though everything is normal. But after attending Billy's funeral, he heads home for a pretty unwelcome surprise.

Return with the Elixir

Waiting in Colin Sullivan's home is Sergeant Dignam, a guy who has known for quite a while that Colin was the rat in the police department. Dignam knows he can't prove anything, so instead he takes justice into his own hands and puts a bullet through Colin's head. So in the end, it's really Dignam who gets to walk away with the last laugh.