Semper Mars (1998)

Amazon.com Product Description (ISBN 0380788284, Mass Market Paperback)

The Year is 2040.

The Marines have landed on Mars to guard the unearthed secrets of an ancient and dangerous alien race: Ourselves.

Scientists have discovered something astonishing in the subterranean ruins of a sprawling Martian city: startling evidence of an alternative history that threatens to split humanity into opposing factions and plunge the Earth into chaos and war. The USMC -- a branch of a military considered, until just recently, to be obsolete -- has dispatched the Marine Mars Expeditionary Force, a thirty-man weapons platoon, to the Red Planet to protect American civilians and interest with lethal force if necessary.

Because great powers are willing to devastate a world in order to keep an ancient secret buried. Because something that was hidden in the Martian dust for half a million years has just been unearthed . . . something that calls into question every belief that forms the delicate foundation of civilization . . .

Something inexplicably human.