An already disastrous Thanksgiving dinner is interrupted when Daniel Tate gets a phone call, his beloved grandfather is dead. It’s September Gale’s first case as a detective. An elderly man is brutally murdered and leaves behind a baffling set of clues to his murder. Within the clues are the secrets to solving his death. The victim’s grandson was the last to see him alive, and is now her prime suspect. As she digs into the crime scene, she is drawn deep into a 500 year-old mystery, and to make matters worse, someone is trying to kill her. Against the warning of her superior officer, Gale solicits the help of her prime suspect, knowing without his help she has no hope of solving the case. The stakes are raised when Gail and Tait are both in the cross-hairs of the assassin who is every bit as determined to piece together the puzzle ahead of them. Time is running out as the ruthless killer anticipates their every move, chasing them through the streets of Portland, Oregon and across the Atlantic to a small town in France. In a frantic race, Gail and Tait find themselves matching wits with a cold blooded murderer hell bent on keeping them from discovering the final thread to an ancient mystery.