When Will accidentally creates a mysterious portal during a trip to the zoo, he's transported into the world of the Night Zoo, and thrust into an incredible adventure. Joined by his friends, Sam and Riya, Will journeys to Fire Desert, where rumours of a creature called 'the Grip' have struck fear into the hearts of the animals. Even Captain Claw, a fierce lioness, seems to be acting strangely on hearing the news. The animals look to Will to save them, but does he have the strength to overcome his fears, and become the hero that the Night Zoo needs?