The Echo Protocol

She walked away from profiling murderers. Now one is playing games only she can solve.

Years after a botched case drove her into seclusion, former criminal profiler Elise Hartmann lives a quiet life designing logic puzzles—until a mysterious package arrives. Inside: a puzzle only she could decipher and a photograph that should not exist. The child Elise failed to save… may still be alive.

Drawn back into a dangerous web of secrets, Elise discovers a series of cryptic clues, each tied to a new disappearance—and a shadowy organization known only as Echo. The deeper she digs, the more disturbing the truth becomes: this isn't revenge. It's a recruitment.

With her own mind unraveling and no one she can trust, Elise must confront her buried past, outthink a brilliant adversary, and survive a deadly game designed just for her.

Perfect for fans of The Girl with the Dragon Tattoo, Gone Girl, and The Silent Patient, The Echo Protocol is a gripping psychological thriller filled with dark twists, chilling revelations, and a protagonist you won't forget.