movie trailer (apple.com - quicktime)
NOTE: This spoiler was sent in by Bp9Y.
The movie opens at a bank where several heavily armed men with machine guns have taken hostages and are engaged in a shoot out with police. The police surround the building and put two cops in an air duct inside, Jim Street(Colin Farrell) and Brian Gamble(Jeremy Renner). When one of the robbers takes a hostage and looks as if he is about to kill her, Gamble defies orders to stand down and proceeds to intervene, with Street following, to take down the robber. In the ensuing gun battle the remaining robbers are killed and the hostage is wounded.
Later we see Street and Gamble in Captain Fuller's office where they are told that due to their defiance of orders they are demoted to "the cage." Gamble doesn't take kindly to this as he believes he saved lives and storms out. Street remains and Fuller tells him that if he says that Gamble was the only reason they defied orders that he can go back to SWAT tomorrow.
Later Street and Gamble are in the locker room arguing and it ends with Gamble quitting the force altogether while Street remains.
The camera cuts away to six months later. Street is working in "the cage" which is basically just a cleaning/repair shop for SWAT cars and equipment. Sgt. Hondo(Sam Jackson) comes in and has his specialty gun cleaned. He is impressed with Street's knowledge of weapons and especially his idea to create a device to tear down walls by using a grappling hook.
Later on Hondo and TJ (Josh Charles) are having a contest to see who is a better shot while running, TJ wins but Hondo convinces Street to enter the contest and he promptly defeats TJ. We are then informed that Hondo has been put in charge of creating a new SWAT team as a way of revamping the police department's image. Hondo recruits Street to drive him around as they go and pick up Deke (LL Cool J) and Chris Sanchez (Michelle Rodriguez) to be members of Hondo's new SWAT team. Hondo then offers Street a position on the team and he takes it. Other members of the team include Boxer(Brian Van Holt) and TJ. Fuller and Hondo then meet and after some back-and-forth the team is approved.
Here is a long drawn out training montage and eventually the team becomes molded together after some early quibbles (Street just broke up with Boxer's sister).
Their first test is on an airplane where hostages and terrorists are intermixed with passengers, the team passes with flying colors. Later after a brief celebration Street and Sanchez go out for drinks and run into Gamble. There is some more back-and-forth but one can clearly see that Gamble hates Street for being on SWAT and SWAT for hiring a woman.
Street goes to Sanchez's house to help celebrate her daughter's b-day but the team is called together to bring in a man who barricaded himself in his house. This goes over without too many problems as they use Street's grappling device to tear a whole in the wall.
During all this the movie cuts into a brief subplot involving Alex Montel(Olivier Martinez). He arrives on a plane and proceeds to a restaurant to meet his uncle where he informs him that he is taking over the family drug business and then kills him. He takes his uncle's car and leaves, but is pulled over for having a broken tail light and is taken into custody because there is a warrant for the arrest of his uncle(the cops dont know he is dead). They eventually discover who Alex really is and plan to have him transported to a federal facility, but not before some of his gang members try to break him free. They are stopped, however, by Hondo's SWAT team in a brief shootout.
On his way back to jail Alex yells to the news cameras that he will offer $100 million to whomever breaks him free. Hondo's SWAT team is in charge of moving him to a federal prison but their plans don't go very well as the helicopter that is meant to take him gets shot down by Gamble using a high powered rifle. They send a decoy convoy out that is attacked by street gangs while Alex is really transported underground. At night they go in a much smaller convoy(two cars) and attempt to move him, but TJ turns on the group and breaks Alex free with the help of Gamble. After a chase through the sewers the SWAT team eventually catches up to the fleeing Alex, Gamble and TJ at a bridge where a hijacked plane lands to take them away. Hondo's SWAT team is the only one there because all the other cops were sent to the airport in a ruse by Gamble. Hondo drives his car into the plane and prevents it from leaving. Deke tackles Alex and brings him in while TJ kills himself.
Street and Gamble go mano a mano and it ends with Gamble getting run over by a train. The team then takes Alex to prison and on the way home they get a call of a robbery in progress.
They decide not to go home.