Zombillenium, the Halloween theme park, happens to be the one place on earth where real monsters can hide in plain sight. When Hector, a human, threatens to disclose the true identity of his employees, the Vampire Park Manager has no other choice but to hire him. To see his daughter, Hector must escape from his zombie and werewolf co-workers.

Growing up in the Wild West and raised on the exciting stories told by his father, Billy with his cowboy outfit has a burning desire to hit the trail! And since every new day offers an opportunity to go on an adventure worthy of the greatest cowboys, he is determined not to miss out… He takes with him his faithful friend Jean-Claude and his accomplice Suzie and off they go!