18 books in series
Sigma Force
Sigma Force is a 25-book series with 18 released primary works first released in 2004 with contributions by James Rollins and Steve Berry.
| #1 |  Sandstorm
| 3.74 | 81 reads | ||
| #2 |  Map of Bones
| 4.13 | 66 reads | ||
| #2.5 |  Kowalski's in Love Kowalski's in Love
| 4 | 3 reads | ||
| #3 |  Black Order
| 4.15 | 47 reads | ||
| #4 |  The Judas Strain
| 4.09 | 50 reads | ||
| #5 |  The Last Oracle
| 4.21 | 47 reads | ||
| #6 |  The Doomsday Key
| 3.82 | 43 reads | ||
| #6.5 |  The Skeleton Key The Skeleton Key
| 3.79 | 25 reads | ||
| #7 |  The Devil Colony
| 3.86 | 38 reads | ||
| #7.5 |  Tracker
| 4 | 16 reads | ||
| #8 |  Bloodline
| 4.12 | 40 reads | ||
| #9 |  The Eye of God
| 4.09 | 39 reads | ||
| #9.5 | The Devil's Bones The Devil's Bones: Cotton Malone vs. Gray Pierce
| 4 | 1 read | ||
| #10 |  The 6th Extinction
| 3.96 | 30 reads | ||
| #10.5 |  The Midnight Watch The Midnight Watch
| 4 | 10 reads | ||
| #11 |  The Bone Labyrinth
| 4 | 37 reads | ||
| #11.5 |  Crash and Burn Crash and Burn
| 3.71 | 10 reads | ||
| #12 |  The Seventh Plague
| 3.9 | 31 reads | ||
| #12.5 | Ghost Ship Ghost Ship
| 3.75 | 10 reads | ||
| #13 |  The Demon Crown
| 4.22 | 30 reads | ||
| #14 |  Crucible
| 4.02 | 28 reads | ||
| #15 |  The Last Odyssey
| 4.11 | 23 reads | ||
| #16 |  Kingdom of Bones
| 3.81 | 20 reads | ||
| #17 |  Tides of Fire
| 4.44 | 12 reads | ||
| #18 |  Arkangel
| 4.8 | 6 reads |