On the trail of Nizca, the vampire who orchestrated the plan to shroud the sun in shadow, the PCs discover the basement of the central command tower of the former prison. They must ascend the tower from within, fighting past deadly guardians and strange Azlanti magic and machinery, to reach the tower's top where Nizca races to repair their device and successfully blot out the sun so they can reunite with their lover to the east. Can the PCs stop night from falling over Golarion?

"To Blot Out the Sun" is a Pathfinder Adventure for four 7th-level characters. This adventure concludes 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 includes a look at a Nin, patron of the campaign's villain and god of mathematical laws of undeath, reveals unsolved mysteries, delves deeper into vampires, and provides a toolbox of magical contraptions and techniques as well as a bestiary of shadowy 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.