Wherever Christopher Rowe goes, adventure--and murder--follows. Even a chance to meet King Charles ends in a brush with an assassin.

All that's recovered from the killer is a coded message with an ominous sign-off: more attempts are coming. So when Christopher's code-breaking discovers the attack's true target, he and his friends are ordered to Paris to investigate a centuries-old curse on the French throne. And when they learn an ancient treasure is promised to any assassin who succeeds, they realize the entire royal family is at stake--as well as their own lives.

In the third heart-pounding installment of the award-winning Blackthorn Key series, Christopher, Tom, and Sally face new codes, puzzles, and traps as they race to find the hidden treasure before someone else is murdered.