The Fourth Weapon. A Horus Thriller, #2

Some weapons are built to kill. The Fourth Weapon was built to make murder look like nature. Six months after surviving Horus, Brooke "Shotgun" Woods is no longer a recruit. She now commands the island base, training a new generation of operatives while trying to rebuild an organization founded on secrecy, manipulation, and carefully buried truths. Then intelligence surfaces about the Fourth Weapon-a biological attack engineered to resemble a naturally emerging outbreak.
The original research was supposedly destroyed years ago. Now someone is preparing to complete it and place it in the hands of a buyer powerful enough to erase every trace. Shotgun's investigation leads from private auctions and covert brokers to abandoned facilities and hidden Horus archives. But every answer reveals another lie, and the evidence points toward someone operating from within the organization itself.
Then she comes face-to-face with the man she buried without a body. Lucas Hernandez is alive. He is working inside the enemy organization. And he may be the only person who knows who is truly building the weapon. To stop an attack the world may never recognize as deliberate, Shotgun must decide where her loyalty belongs-and whether protecting Horus means exposing the truth that could destroy it. The Fourth Weapon is the second novel in the Horus Thriller series, a cinematic espionage thriller filled with covert operations, biological warfare, fractured loyalties, and the devastating cost of choosing the harder right when no one is watching.
Begin the series with Three Good Weapons.