Nate the Great and the Phony Clue (Nate the Great Series)

Early one morning, a torn slip of paper with the mysterious letters V I T A appears on Nate the Great's doorstep. He and his faithful dog, Sludge, set off to solve this latest mystery. Against ferocious cats, hostile adversaries, and a sly, phony clue -- not to mention a three o'clock deadline -- Nate struggles to prove, once again, that he is Nate the Great.