Burning Sky (Codename Quicksilver #3)

Zak Archer is a spy. He works for Project 17 -- a government agency so secret, it officially doesn’t exist. To protect national security, Zak must pose as teen piano prodigy, Alexi Roman. It should be easy, but someone really wants Alexi dead. Who are they? And what is their connection to a planned terrorist attack? Only Zak and his fellow agents can solve the puzzle, but time is running out.