Rex is far from your average teenager - infected by nanites, he's turned into an `Evo', with the power to grow machines out of his body. Unlike other Evos, however, he can grow them to suit a specific need and then reabsorb the machines back into his body. He can also communicate with other machines, and he does his best to help cure Evos of their mutations. Recruited by an organization called Providence, which is dedicated to stopping the Evos, Rex investigates other biological mutations worldwide.