Wynonna is a present-day descendant of the famous lawman Wyatt Earp, and she is the top agent for a special unit known within the US Marshals as the Monster Squad. She battles such supernatural threats as Bobo Del Rey and his redneck, trailer-trash vampires who are pushing a new killer designer drug called "Hemo", and the Egyptian mafia's mummy hitman, Raduk, Eater of the Dead, who is out to do in all the other crime bosses. In her subsequent adventures, she finished some outstanding Earp family business while dealing with Hillbilly Gremlins and Zombie Mailmen alongside her fellow marshals.