The Eye of God: A Sigma Force Novel (Sigma Force Series Book 9)
The Devil Colony: A Sigma Force Novel (Sigma Force Series Book 7)
The Doomsday Key: A Sigma Force Novel (Sigma Force Series Book 6)
The 6th Extinction: A Sigma Force Novel (Sigma Force Series Book 10)
The Last Oracle: A Sigma Force Novel (Sigma Force Series Book 5)
The Bone Labyrinth: A Sigma Force Novel (Sigma Force Series Book 11)
The Judas Strain: A Sigma Force Novel (Sigma Force Series Book 4)
The Seventh Plague: A Sigma Force Novel (Sigma Force Novels Book 12)
Black Order: A Sigma Force Novel (Sigma Force Series Book 3)
The Demon Crown: A Sigma Force Novel (Sigma Force Novels Book 13)