When $60 million worth of stolen diamonds destined for a relief charity end up in the hands of casino owner Jack Catlin, MacGyver must head to the Virgin Islands to try and get them back. With the help of Chris Rhodes, a senator's daughter, MacGyver masterminds a plan to break into Catlin's vault and steal them back.

A mysterious person who calls himself "Viking" has just bombed the cruise ship Victoria, underway in the North Pacific Ocean. He demands six million dollars or another bomb will go off within hours. So MacGyver gets called in, along with his old Vietnam bomb-defusal partner, Charlie Robinson, to disarm it. But when they get there, they find out there's more than one bomb on the ship. Complications arise when MacGyver's partner sets off one of the bombs, and the bomber decides that DXS operated in bad faith and refuses to hand over the bomb-disarming instructions after he gets the extortion money.

MacGyver puts up Penny Parker for a few days while she's looking for a job as a singing telegram. But on her first day, she happens to witness two thugs torturing a man. Unfortunately, she can't find her way back, and when she does, MacGyver thinks this may be the start of something bigger as the victim is a Federal agent.