Minette is kidnapped and held for ransom by Malcolm Macbeth. Jimmy confers with Jessica and decides to try duping the bad guy by substituting the diamonds. The criminal, not being stupid substitutes the cat. Jimmy is snatched from the beach in reprisal and a threatening call is made to the castle. The bad guys have no idea what they are up against. The Cummings family is no ordinary bunch of Americans. Malcolm Macbeth is trying to branch out on his own. He holds Jimmy and the cat in an old disused lighthouse north of the Isle of Skye. Jessica followed by Alistair and Valerie come to the rescue.