The Genius Wars Genius Series, Book 3.

After abandoning a life full of deception and mistrust, fifteen-year-old Cadel has finally found his niche. He has a proper home, good friends, and loving parents. He's even studying at a real university. But he's still not safe from Prosper English, who's now a fugitive from justice and determined to smash everything that Cadel has struggled to build. When Cadel's nearest and dearest are threatened, he must launch an all-out attack on the man...