Cage plays Johnny Blaze, which is the sort of name that can only be a comic book character or a porn actor, and Johnny is the former. He's a daredevil motorcyclist who, in the movie version of the story, sells his soul to the devil in order to save his father's life. He kind of signs the contract accidentally, though, and then his dad dies anyway, so it's really a bummer of a deal. The devil is played by Peter Fonda, but it's a cheesy enough role that Christopher Walken probably should have done it.
Anyway, ol' Mephistopheles keeps Johnny alive for many years (despite Johnny's frequent bike wrecks) and then comes a-callin' one day with a task. Seems the devil's son, Blackheart (Wes Bentley), and his three demonic cronies are looking for a particular contract for a particular batch of souls, and Dad doesn't want them to find it. So Johnny is transformed into Ghost Rider and sent to stop them.
When Johnny is Ghost Rider, his head becomes a burning skull, his torso becomes far more muscular than Nicolas Cage's torso has ever been, and his motorcycle is made of flames. He can crack burning chains like whips, and he can look into a bad guy's eyes and deliver such delightful pronouncements as "Your soul is stained by the blood of the innocent." You show me a man who can say that with a straight face, and I'll show you a man who has burning skull instead of a face.
Johnny doesn't really like having to do the devil's bidding, but his real enemy now is Blackheart, who wears a fitted black trenchcoat and smiles in a sinister fashion and generally behaves like the Goth kids you knew in high school, only gayer.
To complicate matters even further, Johnny is unexpectedly reunited with Roxanne (Eva Mendes), his girlfriend from long ago. She is now a TV news reporter for, I assume, The Cleavage Channel, and she still pines a little for the Johnny Blaze she knew all those years ago, the one whose head didn't catch on fire every night.
The film was written and directed by Mark Steven Johnson, who did a similarly lame job with "Daredevil" a few years ago. That debacle had some amusing supporting characters, though; "Ghost Rider" is superficial and ridiculous in every way, with only Sam Elliott as a grizzled old cemetery caretaker doing anything memorable.
Cage seems to be enjoying himself, I'll say that much for him. The first time Johnny transforms into Ghost Rider, a process that involves being consumed with fire, Johnny is for some reason cackling like a maniac. Soon I was laughing, too, because who laughs when their head catches on fire? What actor would even think that having his character laugh in that situation would be a good idea? Nicolas Cage, ladies and gentlemen. Gotta love him.
But then the dialogue is full of garbage like this, spoken when Johnny encounters a demon made of wind: "Time to clear the air." Factor in Eva Mendes' hilariously unconvincing performance as the TV reporter, the convoluted and muddy storyline, and the general lack of thrills or excitement, and you've got yourself a big, silly comic book movie. Whoever the inept Mark Steven Johnson had to sell his soul to in order to get put in charge of two big comic adaptations, I hope it was worth it.