Bloodline: A Sigma Force Novel (Sigma Force Series Book 8)

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)