Set in the English Lake District, Abigail, Imogen and Ross, the young heroes of the story, are enjoying a well-deserved holiday when they accidentally become involved with a group of drug smugglers. The smugglers, a far from friendly group of men, have a hideout in the workings of a long disused copper-mine and the trio are set to have some hair-raising adventures, and put themselves at considerable risk, as they find themselves fighting for their lives whilst trying to save an undercover policeman and bring the criminals to justice.