The five friends George, Julian, Dick, Anne and Timmy the dog, go for the first time together on holiday. Without parents they set out on a bike ride that takes them into the legendary Cat Canyon. Already at the first bonfire siblings George and Dick make her friends fear and tell the story of the 'Black Cat'. According to legends a thief should have hidden the largest diamonds in the world, the green emerald in the Cat Canyon. And a few seconds later comes a figure out of the bushes. It is the small Hardy who lives in the area and has nothing better to do than to show off his phone and his quad. Although they become friends soon. But what they do not know is that Hardy is followed by the two crooks Max and Fil...—Dimitris Kamitsis

Julian, Dick, shepherd dog Timmy and the girls spend an unsupervised biking holiday into the Cat Canyon, where the legend of the Black cat plays, a mysterious Zorro-like figure who saved the largest emerald from being stolen form a monastery statue, centuries ago. Wandering into a large estate, they meet and befriend Hardy, a silver spoon boy who accepts being neglected by his tycoon father, allegedly the distant heir of the cat, who sort on joins the gang with his motorcycle, quad and robot dog. Hardy's father former business partner hired dumb goons Max and Fil to kidnap the boy to demand the stone as ransom, but they mistake Dick for him, hence kidnap him. The gang tracks them down to the manor, sneakily liberates Dick, only to be all caught with Hardy identifying himself. The mastermind and the kids solve the clues to the gem's hiding place, where a final fight ensues.—KGF Vissers