Walker and the others are presently pursuing some armed robbers whom they dub the Warehouse Cowboys because they hit warehouses. Gage and Cooke corner them at their latest heist and gun battle ensues and one of the cowboys is shot but the leader throws a grenade at Gage and Cooke and they get away. Walker intsructs them to do a background check on the one who was shot. At a research a facility, a scientist is talking to someone from the military about the project he was contracted to do. He tells them that it's ready to be delivered. So he sends his security man Becker to deliver it. Which he does but on the way to the base their convoy is ambushed. Becker manages to get away but them pulls a gun on his driver and shoots him and their vehicle crashes. Then the ambusher arrive and take the case with the device from Becker who tells them that he will be in contact. Walker upon learning of the robbery goes to the facility and is told by the scientist that the device called a thunderhawk is a sonic laser which can be used for many things such as medical treatments but also for military purposes. Walker and Trivette asks for name of everyone at the facility who may have known about the route. Trivette does a background check and learns that everyone is clean. Walker then asks about Becker and he tells him that he has worked there for three years and prior to that was security chief at the airport. Gage and Cooke tell Walker that the man they shot is a Gulf War Vet and that he was associated with some wildcards the leader of whom is a guy named Deke. Deke and the others are commiserating over their fallen comrade and are planning their next job. Becker is at the airport warehouse with his associates talking to the buyer a man named Faisal telling him that he can pick up the Thunderhawk when he wants. It is then that Deke and the cowboys come in. It seems they are there for the computers that are stored there. But then Deke sees the Thunderhawk and takes it. It is then that Becker and the others shoot at them. Two of Becker's men are killed. Deke throws a grenade at them and gets away. Becker instructs his man Jackson to find them. Walker and Trivette arrives and knowing that the Cowboys are behind the whole are wondering about the gun battle. Walker then finds the manual for the Thunderhawk and wonders why it's there. Walker recalls that Trivette said that Becker worked there before. Deke upon learning what the Thunderhawk decides to sell it. Jackson gets a lead on Deke and he and Becker arrive and demand they return the Thunderhawk, when they refuse Becker shoots one of them. They take him to it and they give it to him. Becker leaves but not before using the Thunderhawk on the bulding they are in bringing it down. Walker arrives and realizes that this was all the work of the Thunderhawk. He and Trivette go back to the facility looking for Becker but learn that he has taken a leave of absence. Trivette looks at his computer and discovers that he has been corresponding with someone in the middle east. They learn about Faisal who is obviously anti-American. Faisal takes possession of the Thunderhawk and Jackson asks what he is going to do with it. When he tells him that he is going to commit an act of terrorrism Jackson tries to attack him but is killed. He leaves. Walker arrives and apprehends Becker. They tell him that he is in a world of trouble, he tells them where Faisal is. Faisal's about to take off when Walker and the others arrive. While dealing with Faisal's people, Faisal tries to escape but Walker who read the manual uses the Thunderhawk on Faisal's plane stopping it.