Arkangel: A Sigma Force Novel

The 6th Extinction: A Sigma Force Novel

Sandstorm

Crucible: A Thriller

Kingdom of Bones: A Thriller

The Doomsday Key: A Sigma Force Novel

The Bone Labyrinth: A Sigma Force Novel

The Eye of God: A Sigma Force Novel

Bloodline: A Sigma Force Novel

Map of Bones: A Sigma Force Novel

The Seventh Plague: A Sigma Force Novel

The Devil Colony: A Sigma Force Novel

Tides of Fire: A Thriller