From the back of the adventure:
"Sometimes You Eat the Worm, Sometimes the Worm Eats You...
Ronan Lynch wasn't looking for trouble when he came to the small town of Hilton Springs, Nevada. Of course, he hadn't counted on running into his old "friend" Texas Ranger Hank Ketchum. Or on being in town when the local population of Mojave rattlers start getting restless. Before long, folks were disappearing down into the earth at a positively alarming rate!
But these worms weren't after a meal. The rattlers around Hilton Springs seem to be up to something unspeakably unnatural and evil. It's up to Ronan and Hank to put a stop to them-or end up as worm food in a very literal way!"