An art dealer's wife is taken hostage, with the kidnappers demanding a set of valuable diamonds in exchange for her life. The husband goes to the police for help because his wife has swallowed the diamonds, and he fears that if this is revealed, the kidnappers will kill her to get them. Events spin rapidly out of control when it is revealed that DCI Reed had knowledge of the robbery, and allowed it to go ahead in exchange for a portion of the profits. Reed kills his criminal contact to cover his trail, and then the kidnapper himself. He flees, finally killing Zoe in an attempt to draw Luther out, framing Luther for the crime.