Sigma Force

1 Sandstorm (2004)
2 Map of Bones (2005)
2.5 Kowalski's in Love (2006)
3 Black Order (2006)
4 The Judas Strain (2007)
5 The Last Oracle (2008)
6 The Doomsday Key (2009)
6.5 The Skeleton Key (2011)
7 The Devil Colony (2011)
7.5 Tracker (2012)
8 Bloodline (2012)
9 The Eye of God (2013)
10 The 6th Extinction (2014)
10.5 The Midnight Watch (2015)
11 The Bone Labyrinth (2015)
11.5 Crash and Burn (2016)
12 The Seventh Plague (2016)
12.5 Ghost Ship (2017)
13 The Demon Crown (2017)
14 Crucible (2019)
15 The Last Odyssey (2020)
16 Kingdom of Bones (2022)
17 Tides of Fire (2023)
18 Arkangel (2024)

The Doomsday Key / The Last Oracle (2013)
Sigma Force Novels 1 (2014)