Loyalty can hold a crew together — or tear it apart.

After surviving the hell of Varissi, Petty Officer Tahir Marcus finds himself aboard the Thresher, a battered starship assigned to patrol the volatile Disputed Zone. With alliances crumbling and whispers of war spreading across the sector, Marcus soon realizes the ship's greatest dangers aren't outside its hull — they're within it.

The Thresher is failing, its crew divided, and its officers hiding secrets that could ignite a galactic conflict. Caught between duty and survival, Marcus must navigate shifting loyalties, fragile alliances, and betrayals that cut deeper than any enemy fire.

In the Disputed Zone, one wrong decision can doom not only a starship but the fragile peace of entire systems. Marcus must uncover the truth before both the Thresher and his future are lost forever.

The Thresher continues The Marcus Files, a military space opera filled with loyalty, secrets, and survival — perfect for fans of The Expanse, Jack Campbell's Lost Fleet, and John Scalzi's Old Man's War.