Some weapons are built to kill. The Last Weapon was built to prove that no one is truly free.

For a year, Commander Brooke "Shotgun" Woods has rebuilt Horus into something its founders never intended?an organization governed by truth, consent, and trust.

Then the scattered fragments of Astrid Kessler's abandoned weapons program begin disappearing from the black market.

Someone is buying them back.

His name is Osiris: the presumed-dead founder of Horus, the architect of its oldest doctrine, and the man who trained both Astrid and Anubis. For thirty years, he has remained hidden, watching the organization he created and patiently preparing to finish the work Astrid tried to destroy.

Now he has someone inside Horus.

Someone trusted. Someone who was never recruited or turned?because their loyalty belonged to Osiris long before Shotgun knew there was a war.

With every operation compromised and every member of her command circle under suspicion, Shotgun must form an impossible alliance with Anubis, the enemy who destroyed her life and may be the only person alive who understands the man coming for them.

But the final weapon is more than a device.

It is the culmination of an argument thirty years in the making: that people can be studied, shaped, and pressured until even compassion becomes another instrument of control.

To stop Osiris, Shotgun must enter the heart of the program and prove that the most powerful weapon any person possesses is the one thing no architect can design for them:

The person they decide to become.

The Last Weapon is the explosive and emotional conclusion to the Horus Thriller trilogy?a gripping story of espionage, betrayal, sacrifice, redemption, and the choices that remain when every other freedom has been taken away.

Begin with Three Good Weapons, continue with The Fourth Weapon, and complete the Horus trilogy with The Last Weapon.