From the Publisher:

The almost-human Closers are waging a war of mutilation, annihilation, and extermination across a million alternate timelines. To stop them, Crux Ops recruits fighters from Earth's every era.

Pittsburgh private eye Mark Strang has his own personal score to settle with the aliens. Trained with nightmare weaponry (and teamed with the woman of his dreams) Strang is sent Closer-hunting, to an alternate 1776 where George Washington is Duke of Kentucky, and Strang's most vicious enemy is - his alternate self!