Pete Garrison is on the presidential protection detail when another Secret Service agent is murdered. An informer tells Garrison about an elaborate assassination conspiracy that is related to this murder and is well underway. Garrison also happens to be having an affair with the First Lady, the stress of which causes him to flunk a lie detector test when word of the plot to kill the president becomes more than just paranoia. Garrison is soon on the run, being hunted by his protege David Breckinridge. But Garrison is at the top of his game and he knows all of the secret service tricks and uses them to evade his former comrades as the clock ticks down to assassination.