Smith stars as a man who goes by the adoptive name of John Hancock, having forgotten his true identity decades earlier thanks to amnesia. Hancock is a super-powered being who is faster than a speeding bullet, more powerful than a locomotive, and able to leap tall buildings in a single bound. He is also an alcoholic with little regard for anyone or anything. Whenever he shows up to save the day, he causes so much damage that he is seen by the public as more of a problem than a solution. While stopping a gang of trigger-happy gunmen racing along the freeway, Hancock destroys the freeway itself, a fleet of cop cars and several buildings before leaving the gunmen's car impaled on the spike atop the Capitol Records building. This is just one of many incidents that has outraged the public, which Hancock seemingly holds with little regard.

Hancock comes to the rescue of Ray Embrey (Jason Bateman), a public relations consultant whose career is quickly going down the toilet. As a sign of his gratitude, Ray offers to help Hancock reinvent his public image, and turn him from a superpowered jackass despised by most, to a superpowered hero loved by all. The first step is getting Hancock to turn himself in when a warrant is issued for his arrest. While in prison, Hancock is forced to give up booze, and deal with his anger issues. But while he is in jail, the crime rate rises dramatically, and eventually the police must call on him to save the day, leading Hancock down a path that will see him living up to his true potential as a hero.

Hancock is not a terrible movie, at least not until it gets to the third act, when the whole thing quickly falls apart. The film starts with a solid and promising premise, but it lacks any driving intelligence to sustain it. The script itself, which had languished unproduced for over a decade, really could have used some tightening before cameras actually started rolling. For one thing, there is no clearly defined villain in the film--at least not one worthy of Hancock's incredible powers. This lack of a compelling antagonist means that the film also lacks any true conflict. And what conflict there is arises from the same stupid plot twist that threatens to bury the movie as it prepares to go into the second act. There is literally a moment where the film takes a sudden turn, and everything begins to unravel from there.

The script, written by Vincent Ngo and Vince Gilligan, is a series of jokes and scenarios strung together by a premise that is never fleshed out as an actual story. The result is a film that is initially entertaining--even if it is in a no-brainer sort of way--but starts to fall apart when it needs to show some semblance of intelligence. The film has no sense of real relationship between the characters, nor does it have any true sense of time. The friendship between Hancock and Ray, as well as Ray and his wife Mary (Charlize Theron), seem to be there merely as a way to propel the concept of the film--not even the story itself--forward. By the time the film reaches its climatic showdown, you're left with the sinking feeling of, "Damn, I don't think it's going to get any better than it was an hour ago."

Fans of Smith should enjoy the film overall, despite its flaws. And even though he is more convincing as the reformed Hancock, free of booze and looking to redeem himself, he never quite makes the whole package work. It would have been nice to see someone like Dwayne "The Rock" Johnson in this role, as he has more of what it takes to come across initially as a bad guy. But Will Smith is what we have to work with, and he does the most he can with a flimsy story and a weak script.

As a bit of cinematic eye-candy, the first half of Hancock is entertaining enough that it's worth watching, and the film is filled with enough bombastic special effects that it begs to be seen on the big screen. The problem, however, is that if you commit to the first half of the film, you're obligated to watch the second half, which is not even close to being as good as it should be.