Having finally arrived safely in the Deep Woods (see D077 The Monkey Mail), Diana is invited to watch the preparations for the Jungle Olympics, a very demanding competition started by one of the Phantom's ancestors as a substitute for senseless killings.

Meanwhile, two hoodlums on probation are ordered by Colonel Weeks to act as jungle guides for a butterfly collector. But the troublemakers' new-found discipline is tested to the limits when they stumble upon the unguarded Phantom Trophy, a magnificent, jewel-filled prize awarded to the winning tribe...