Leo, a boy with neurofibromatosis, is visiting New York with his family after some treatment. But everywhere they go, mysterious things keep happening. The T-Rex at the American Museum of Natural History comes to life. The ice rink in Central Park transforms into mountains of ice. Then something is making people sick all over the city.

In each case, Leo - together with his dog, Clark - uses his hidden powers to tackle the dangers and save others. But what could be causing all these strange events? Are they connected? When Leo spots a green light coming from the Empire State Building, it's up to him and Clark to solve the mystery and find out what, or who, is behind it. He'll find out it's not only his hidden powers but also his diagnosis that make him the perfect hero for the moment.