From the back of the adventure:
"That's Some Fireworks!
Celebrate the Fourth of July in the Disputed Lands!
Ever since he turned up dead, Ronan Lynch has been wandering around the Weird West, trying to stay out of the trouble that follows him around like a hungry bear. This time, his travels have taken him to Dodge City, the unofficial capitol of the Disputed Lands, right on the Fourth of July. There Ronan takes a job with Wyatt Earp to help keep the peace. Now, though, he must contend not only with Rebels and Yankees at each other's throats, but also a mysterious serial killed known only as the Butcher."