From publisher blurb:
The Tunnels that Time Forgot!
Warning! Some assembly required! This book contains everything you need to run an adventure, including several new stat-blocks, adventure background, and an outline of encounters. What it does not include are maps and read-aloud text. GMs will need to connect the dots in a few places to fit the encounters and overall plot of this micro-adventure into their larger campaign.
Adventure paths offer fantastic stories and sweeping campaign arcs that take characters on a ride from very low levels all the way up to the highest reaches of the game, and they can be incredibly fun and rewarding to play. But even though there’s a lot packed into an adventure path, sometimes you find yourself wishing for more, whether there’s a part of the adventure path that feels like it got a bit rushed or cut due to space issues, or just a fun little side trek to take a breather before jumping back into the action of the main story. Side Paths provides just this sort of content, with micro-adventures designed to fit into portions of existing official Paizo adventure paths, but which can easily stand on their own, or be inserted into other, similar campaigns.
In this adventure for a party of 12th- or 13th-level characters, designed to occur in the later stages of the adventure path from Paizo, Inc that focuses on the tropical ruins of an ancient civilization, the colony from which the party has been operating is attacked by hordes of morlocks, who drag off captives back to their lair. The adventurers must track the morlocks to their twisting, honey-combed warren and face down their leader, a powerful worm-that-walks priest who has been tearing at the fabric of time itself. Can your party brave the tunnels of the twisting worm?