From the description:
From a crater lake on an island off the coast of Bronze Age Estonia... To a crippled Viking warrior's conquest of England... To the bloody temple of an Aztec god of death and resurrection... Their presence has shaped our world. They are the Riders. One month ago, an urban explorer was drawn to an abandoned asylum in the mountains of northern Massachusetts. There he discovered a large specimen jar, containing something organic, unnatural and possibly alive. Now, he and a group of unsuspecting individuals have discovered one of history's most horrific secrets. Whether they want to or not, they are caught in the middle of a millennia-old war and the latest battle is about to begin.
What a story! The Specimen is an action packed thrill ride filled with complex characters and intense action. At the beginning of the book I wasn't sure who the good guys were because not all of the " good guys " are good people. That quickly gave way to dying to know what would happen next. My only real complaint would be that I want to know more about where the riders come from. Maybe that question will be answered with a sequel ( I hope! ). Great book! Grab it and hold on for the ride! A solid 4 star read.