Cotton Malone
thriller
Series · thriller
Sigma Force
The Sigma Force series by James Rollins has 25 books and is best read in publication order, starting with Sandstorm (2004).
- Books
- 18 novels + 7 novellas
- First published
- 2004
- Status
- ongoing
- Last checked
Start here: Sandstorm (2004) — then read straight through in publication order.
Reading order
The order the books were released — the default way to read the series.
- Book 1:
Sandstorm
Alternative text for cover: Cover of Sandstorm - Book 2:
Map of Bones
Alternative text for cover: Cover of Map of Bones - Book 3:
Black Order
Alternative text for cover: Cover of Black Order - Book 4:
Kowalski's in Love
Alternative text for cover: Cover of Kowalski's in Love - Book 5:
The Judas Strain
Alternative text for cover: Cover of The Judas Strain - Book 6:
The Last Oracle
Alternative text for cover: Cover of The Last Oracle - Book 7:
The Doomsday Key
Alternative text for cover: Cover of The Doomsday Key - Book 8:
The Skeleton Key
Alternative text for cover: Cover of The Skeleton Key - Book 9:
The Devil Colony
Alternative text for cover: Cover of The Devil Colony - Book 10:
Tracker
Alternative text for cover: Cover of Tracker - Book 11:
Bloodline
Alternative text for cover: Cover of Bloodline - Book 12:
The Eye of God
Alternative text for cover: Cover of The Eye of God - Book 13:
The Devil's Bones: Cotton Malone vs. Grey Pierce
Alternative text for cover: Cover of The Devil's Bones: Cotton Malone vs. Grey Pierce - Book 14:
The 6th Extinction
Alternative text for cover: Cover of The 6th Extinction - Book 15:
The Midnight Watch
Alternative text for cover: Cover of The Midnight Watch - Book 16:
The Bone Labyrinth
Alternative text for cover: Cover of The Bone Labyrinth - Book 17:
Crash and Burn
Alternative text for cover: Cover of Crash and Burn - Book 18:
The Seventh Plague
Alternative text for cover: Cover of The Seventh Plague - Book 19:
Ghost Ship
Alternative text for cover: Cover of Ghost Ship - Book 20:
The Demon Crown
Alternative text for cover: Cover of The Demon Crown - Book 21:
Crucible
Alternative text for cover: Cover of Crucible - Book 22:
The Last Odyssey
Alternative text for cover: Cover of The Last Odyssey - Book 23:
Kingdom of Bones
Alternative text for cover: Cover of Kingdom of Bones - Book 24:
Tides of Fire
Alternative text for cover: Cover of Tides of Fire - Book 25:
Arkangel
Alternative text for cover: Cover of Arkangel
About the Sigma Force series
Sigma Force is a covert unit of the U.S. Defense Advanced Research Projects Agency (DARPA), staffed by former special-forces operatives cross-trained as scientists and sent to investigate threats where cutting-edge science and ancient mystery collide. Every novel pairs a real scientific or historical hook — CRISPR gene editing, quantum physics, lost expeditions, ancient plagues, cryptozoology, Norse and biblical lore — with a globe-spanning conspiracy, and James Rollins (a veterinarian by training) grounds even the wildest set pieces in genuine research, laid out in the author's-note that closes every book. The team, led by Commander Gray Pierce, is a true ensemble: linguist Monk Kokkalis, historian Elizabeth 'Seichan' Ang-turned-ally, and a rotating cast of specialists whose personal lives and relationships thread through the mission-of-the-book plots.
Rollins escalates the stakes across the series from single-country crises to genuinely world-ending threats, while keeping each book's central mystery mostly self-contained. Crossover novellas link Sigma Force to Rollins' other series and to Steve Berry's Cotton Malone books, rewarding series-spanning thriller readers. It's a strong pick for fans of Michael Crichton-style science thrillers who also want Indiana-Jones adventure and Dan Brown-style historical conspiracy in the same book.
Frequently asked questions
How many Sigma Force books are there?
There are 18 full-length Sigma Force novels as of Arkangel (2024), plus around seven digital-only short stories.
What order should I read the Sigma Force books in?
Publication order, starting with Sandstorm (2004). Team relationships develop across the series, though each book's mystery is largely self-contained.
Do I need to read the Sigma Force short stories?
No, they're optional extras. The Devil's Bones is a direct crossover with Steve Berry's Cotton Malone series and is best read once you know both series; the rest are skippable character vignettes.
Is the Sigma Force series finished?
No, it's ongoing, though there was no new numbered entry announced in the year following Arkangel (2024) as of this writing — James Rollins has been focused on other projects (a standalone thriller and the Moonfall Saga fantasy series).
Is Sigma Force connected to James Rollins' other series?
Yes. Rollins has written crossover short stories and novels linking Sigma Force to his other series and to Steve Berry's Cotton Malone books.
If you like the Sigma Force series
Reading order last verified .