The plot of Crimson follows a botched robbery attempt at a jewellery store, which goes wrong when one of the gang members, Karl (Victor Israel), surreptitiousy tries to nab a pearl necklace from an alarmed display case. During the frantic escape, another of the robbers, Jack Surnett (Paul Naschy), is shot in the head, leaving their leader, Henry (Oliver Mathot), with a bit of a tricky situation.