In the film, Sean Connery played the part of a spy from a foreign country who stole a film from a camera that had the JFK shooting and other government secrets on it. He also was the only person to escape from Alcatraz, but they later caught him. After that he was locked in a higher security prison were he was marked as dead and everything about him was erased.
Now years later there is a threat to kill all of San Francisco with a new chemical weapon called VX gas (an actual nerve agent). The man who threatened to kill San Francisco was played by Ed Harris. He assembled a team of Marines and Seals to help him take over Alcatraz.
warning: wikipedia contains spoilers
The assault team was able to overrun Alcatraz very quickly, because it was populated only by a few tour guides and tourists. Harris did this because there was no money sent to the men's family that were lost in a war. He set up the missiles that would launch the gas and set up a satellite link to talk to the president and other important people. He then demanded money for the men's families and to pay the men that helped him take over Alcatraz.
Now back to San Francisco the FBI lets out Connery and informs him of the situation, then takes him to get a hair cut where he then hangs one of the agents who captured him over a balcony by his hand with a cord. He ties the cord to the rail and runs away. He gets a man's Hummer and drives off. Cage then aquires a Ferrari and chases after him. In a spectacular car chase scene, he destroys half the city in the process, one of the ways by making a trolley derail.
While the chase is happening Connery finds out where his daughter lives and meets here at a park and gets to talk to her for a minute then the feds show up and take him.
Finally, he complies and he, Cage, and a group of SEALS enter Alcatraz using the same information that Connery had used so many years before to escape from that notorious prison.
They finally get in and enter through the showers and all the Seals are killed by a above ambush. Only Connery and Cage are alive. They disarm all the missiles, but right after a air force bombing annihilates the island, Cage devolped a friendship with Connery and told the Feds that he was dead, but he really was not.
Connery told Cage where the film was and, during Cage's honeymoon with Vanessa Marcil, they stole it. Amusingly, it was hidden in a church where Cage had to break off the leg of a pew to retrieve the film.
wikipedia.org dumped 2003-03-17 with terodump