No Surrender by Dale Lucas is a novella inspired by HP Lovecraft's Cthulhu Mythos.

In the wake of the American Civil War, Union Army Lieutenant Nathan Kenning commands a detachment of peacekeeping troops in Tampa, Florida. Their mandate: to police the area, assist the harried Freedmen's Bureau and defend the thousands of emancipated slaves in the region from Confederate reprisal. Then, one fateful evening, a ragged madman stumbles into town ranting about mass murder and black magic in an adjacent county. War-weary but determined, Lieutenant Kenning leads a small detachment into the swampy countryside to investigate the madman's reports of disgruntled Confederate soldiers running a brutal campaign of terror and murder... and, just possibly, awakening an ancient evil beyond mankind's influence or understanding...