Lightning Days — Colin Harvey

There's a mystery in the caves of Afghanistan. British Special Agent Josh Cassidy knows there is no such thing as a routine mission when he is sent to accompany an ill-prepared band of reservists on a hastily prepared mission into the heart of Afghanistan. The mysterious heat source that showed up on the military satellites could be just about anything, but nobody is prepared to find a group of refugees from an alternate universe: a group of intelligent, NEANDERTHAL refugees. Sophia and her people have shifted universes for years, trying to keep ahead of the vicious race of Sauroids that is intent on exterminating the Thals. Now the long-running battle has come to our universe, and Josh Cassidy is the only man who stands between the Sauroids and the total annihilation of everyone on the planet Earth.