The Banned and the Banished:

• WIT'CH FIRE (1998)
• WIT'CH STORM (1999)
• WIT'CH WAR (2000)
• WIT'CH GATE (2001)
• WIT'CH STAR (2002)

Sigma Force:

• SANDSTORM (2004)
• MAP OF BONES (2005)
• BLACK ORDER (2006)
• THE JUDAS STRAIN (2007)
• THE LAST ORACLE (2008)
• THE DOOMSDAY KEY (2009)
• THE DEVIL COLONY (2011)
• TRACKER (2012)
• BLOODLINE (2012)
• THE EYE OF GOD (2013)
• SIXTH EXTINCTION (2014)
• THE BONE LABYRINTH (2015)

Godslayer Books:

• SHADOWFALL (2005)
• HINTERLAND (2006)

Jake Ransom:

• JAKE RANSOM AND THE SKULL KING'S SHADOW (2009)
• JAKE RANSOM AND THE HOWLING SPHINX (2011)

The Sanguines:

• CITY OF SCREAMS (2012)
• THE BLOOD GOSPEL (2013)
• BLOOD BROTHERS (2013)
• INNOCENT BLOOD (2013)
• BLOOD INFERNAL (2015)

Tucker Wayne:

• THE KILL SWITCH (2014)
• WAR HAWK (2015)

Standalone Novels:

• SUBTERRANEAN (1999)
• EXCAVATION (2000)
• DEEP FATHOM (2001)
• AMAZONIA (2002)
• ICE HUNT (2003)
• INDIANA JONES AND THE KINGDOM OF THE CRYSTAL SKULL (2008)
• ALTAR OF EDEN (2010)