Car detective Jack Colby has a new case, but soon suspects much more is at stake . . . - All is not well on the film set of director Bill Wade's new blockbuster Dark Harvest. At first Jack Colby, car detective, can't believe his luck when he is called in to investigate the disappearance of Bill Wade's rare 1935 Auburn speedster, but he soon realizes that this is no straightforward theft. Jack's warning lights are beginning to flash about his assignment - and rightly so, because the stage is set for murder.