Hero's Journey
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
When the story begins, Michael is already a capable guy. He's not a wimpy dude who needs to overcome his fears and rise to new heights. In fact, he's a war hero. But the problem is that his family is full of criminals. While Michael was out saving America during WWII, his Mafioso dad was subverting the laws of the land, enriching and aiding himself and his friends. Michael assures his girlfriend, Kay, that that's the way his family acts—but that's not him.
Call to Adventure
But circumstances force Michael to forsake a legit future in politics or business: The rival Tattaglia family tries to assassinate Don Corleone. In the aftermath, Michael needs to protect his severely wounded father when the hit men try to finish off the job, and gets punched by a corrupt cop, Captain McCluskey, in the process. He realizes he needs to prepare for revenge.
Refusal of the Call
Michael never really refuses the call to adventure. But he does need to summon the courage to do something he's never really done before—commit murder, finishing off Sollozzo and Captain McCluskey as punishment for trying to kill his father.
Michael fought in World War II, but that was a legal and acceptable form of violence, geared toward defeating the Nazis. Now, he has to develop the nerves required to go outside the bounds of the law, in a big way. Fortunately, he's pretty cool and collected by nature.
Meeting the Mentor
To some extent, the mentor role is filled by Don Corleone. Of course, Michael's known Don Corleone for his entire life, being his son and all, so he doesn't really meet him at this point—and Vito's mentor role is a little subdued, since he never wanted this life for Michael and only gives him advice later on, after recovering from his assassination attempt.
Clemenza, one of Corleone's main men, helps play the mentor role in this earlier part of the movie, training Michael on how to successfully murder McCluskey and Sollozzo, and also urging him to tell Kay that he loves her.
Crossing the Threshold
Michael officially crosses the threshold from All-American war hero to organized crime scion when he blows out McCluskey's and Sollozzo's brains, avenging his father.
Unfortunately, he needs to skip the country, running back to the Old World, Sicily, for safety. The die is cast. After whacking a cop—even a really bad one—there can be no return to normalcy for Michael. He's fully embarked on the gangster's path.
Tests, Allies, Enemies
In Sicily, Michael's problems aren't over. Sheltered by a Don who owes his father, Michael needs to travel with bodyguards. He falls in love with the daughter of a local man and courts her in the Old World style before finally marrying her.
Back home, things are getting worse. The five major mafia families are at war, and the Corleones' lives are all at risk. Michael's brother-in-law, Carlo, turns out to be a vicious wife-beater, attacking Michael's sister. Turmoil reins, although Michael's life seems to be going pretty well.
Approach to the Inmost Cave
Sonny, while racing to punish Carlo for attacking his sister, is murdered at a toll-booth by a pack of mobsters. (He was set up by Carlo.) Back in Sicily, Michael receives the bad news. Things are looking pretty ominous…
Ordeal
One of Michael's bodyguards, Fabrizio, turns traitor. He plants a car bomb intended for Michael, but it ends up killing Michael's Sicilian wife instead. This is probably Michael's greatest crisis—the life he was building for himself suddenly dissolves completely. After his father makes peace with the other mafia bosses, Michael heads back to America, unsure of what the future will bring.
Reward (Seizing the Sword)
Michael hooks back up with Kay and becomes the new acting-head of the Corleone family. His father is too old to continue ruling and basically becomes a professor emeritus of crime, while his other brother, Fredo, isn't competent enough to fill the role. It's left to Michael to help the Corleones fight their way back from near-defeat.
The Road Back
Michael has to deal with some significant obstacles as he seizes the reins. People think they can walk all over the Corleones at this point. Their old business associate, Moe Greene, is running a casino that's losing money and he is thinking of signing on with the rival Barzini family.
Fredo is failing to represent the family's interests in Vegas, and they've been forced to accept the Barzini and Tattaglia families' scheme for controlling the drug business. Don Corleone dies from old age, and Tessio, one of Corleone's trusted allies, turns traitor, attempting to set Michael up for assassination. On the bright side, he decides to marry Kay.
Resurrection
Michael resurrects the family, and himself, through blood. On the day of his godchild's christening—the day that he, Michael, is becoming a literal godfather and the Godfather—he launches a massacre, cleaning out all the Corleones' enemies: Tessio, rival dons like Barzini and Tattaglia, Carlo, Moe Greene, and others.
He's succeeded at becoming the cold-hearted criminal he was always secretly suited to be.
Return With the Elixir
At the end of the movie, Connie (Michael's sister) accuses Michael of having her husband killed on the day of their child's christening—when Michael was becoming their baby's godfather. This is totally true, but Michael straightfacedly denies it. He also tells Kay it's not true.
As a criminal/businessman, the dude has become totally impersonal and capable. He can get the job done, and doesn't mind the blood-soaked costs. But that's kind of the point, as his father's capos all gather to pay their respects to Michael, the new Don. So, congratulations, Mike! You're officially a cold-blooded killer.