Luna has just moved to London with her dad and is feeling anxious about starting at a new school and trying to make friends.

Helping out at an animal rescue centre over the summer, she meets a dog, Silver, who is as shy and wary as she is: they quickly become inseparable. One evening, there is a break-in at the rescue centre, and when Silver smells danger, he transforms into a wolf in a flash of blue light, to protect Luna.

She discovers that her scientist mum was involved in a top secret project to create super pets, including a dog turning into a wolf, a gecko into a crocodile, a cat into a tiger. But the director of the project wanted to sell these animals to collectors on the black market: Luna's brave mum released them into the wild to foil this plan - and now the villain is hot on their trail, determined to capture them again. Luna discovers that she has the ability to power-up the animals; and that she's the hero they need to protect them and stop the villain!