When a prisoner transport plane carrying Deputy Sam Gerard as an escort crashes, one prisoner, Mark Sheridan helps him rescue some trapped prisoners and then escapes himself. Gerard and his crack team of U.S. Marshals start their pursuit, but the simple fugitive situation soon gets more complicated when Gerard learns that Sheridan is no mere criminal and the story behind his incrimination becomes more and more suspicious. At the same time, Mark Sheridan is out to find out the truth himself while keeping one step ahead of Gerard.