When Tess first discovers she's a Switcher - someone who can change shape to become another creature at the bat of an eyelid - she promises herself that she will never, ever tell anyone. She never has.
And, all the while Tess has kept her Switcher secret hidden, she's always felt different - and alone. Until now. Until another Switcher, Kevin, finds her and together they realise what unbelievable, unimaginable powers they possess - when they put their minds to it . . .