Merlin, a mischievous black Labrador puppy, is thrust into an enchanted world where all his make-believe and playful dreams become a reality thanks to his magical red collar. He's joined in his wild adventures by his glamorous canine friend Kizzie and other inhabitants of Sandybay Harbour, including the lazy hedgehog Reg The Hedge; Gull, the surly seagull and Oscar the smart ginger cat who takes every opportunity to land Merlin in heaps of trouble with the harbour residents.