When treasure hunters excavate the long-lost wreck of the Steamship Arcadia from a Kansas corn field, a buried creature awakens - a mindless brute made of accursed earth, shaped like a man, but in no way mortal. A century and a half after its creation, the golem's sole mission resumes: to assassinate a savage pro-slavery guerilla commander named "Bloody Bill" Wolcott. Wolcott, of course, is long dead, but his closest surviving descendant - a corporate IT burnout named Ben Middleton - is quite available. Ben's life hasn't exactly gone according to plan, and he's learned from experience to expect the worst. But he's never faced the kind of doom posed by a 150-year-old mud monster with no "off" switch. And that's not even his biggest problem. Because there's one last stop in Bloody Bill's bloodline: Ben's teenage son, Charley. Ben would do anything to protect Charley - if he doesn't strangle the kid himself first. Ben's only hope lies in a motley crew of protectors: the descendant of the creature's original handler; the intriguing new hire from work; and his fellow nerds from First Floor IT. And if he survives, Ben faces an even worse fate: His 40th birthday is right around the corner.