The remote island settlement of Talmandor's Bounty is thrown into chaos as a strange magical effect plunges the region into shadow. Urged to investigate the event, the PCs travel to a nearby island and discover an ancient Azlanti prison that was buried during Earthfall. Inside, a cult of the blood god Camazotz thrives, and in dealing with them the PCs learn that greater threats lay deeper inside the ancient complex. Can the PCs discover who's behind the supernatural shadow and stop them before it's too late? "Thirst for Blood" is a Pathfinder Adventure for four 1st-level characters. This adventure begins the Shades of Blood Adventure Path, a three-part monthly campaign in which a group of adventurers explore a ruined ancient prison to stop a vampiric threat to cover the skies in shadow. This volume also includes a look into Camazotz, god of bats, blood, caverns, and nocturnal predators, a gazetteer of the island settlement of Talmandor's Bounty, new player options, and a selection of dangerous monsters. Each monthly full-color softcover Pathfinder Adventure Path volume contains an in-depth adventure scenario, stats for several new monsters, and support articles meant to give Game Masters additional material to expand their campaign.