Disguised

Hayden Brandt had one task - find out more about the British millionaire Rhydian Stone, and to eliminate him if he turned out to be what the GSI thought he was, a rogue spy. He was pure evil, rude, intelligent, and harboured dark secrets according to the information they had on him. It was supposed to be simple, but it proved to be otherwise.
Raidon Stone, a seventeen-year-old boy in sixth form. He was her way in.

3, all's at stake;
2 choices to make;
1 mistake;
0, it's all too late.