Heart of Clay (High School Hell #2‪)‬

Samantha Abraham has the power to magically control her boyfriend's every action, but now someone wants that power--and wants him dead.
After the fallout from Heart of Stone, Sam has learned the truth: that her boyfriend, Joshua, was created in a lab by a mysterious scientist known only as The Professor. A magical ruby gives her the power to control him by thought. It seems like the perfect relationship, until a gauntlet of assassins show up in River City with murder on their minds.
On a quest for the truth that takes her to Toronto and into the den of her enemies, can Sam, Duckie, and hockey-hunk Rick save Joshua’s life before it all goes to hell?