The Wizards of Atlantis: Public Enemy

Shane Hollingberry wanted nothing more than a normal good life, but what he got was different. After going on a class field trip to a submarine dock, Shane and his two friends Dioma Yale and Brennan Huff find the real Atlantis. Now Atlantis isn't some regular empire. It was and still is ruled by wizards. After Shane, Dioma, and Brennan visit Atlantis they meet Alexandra "Alex" Cassius who has always lived in Atlantis. Soon the four start attending the "Atlantian Institute of Magic" and discover of a dark wizard (or Public Enemy) named Lord Kratos, who went into hiding 2 years ago and disguised himself as a different person, looking for an old stone called the Water Stone which will make the user ruler of Atlantis. Now that Shane has found the stone, he can't trust anyone but Alexandra, Dioma, and Brennan... Atlantis is about to change.