Astronomers have marveled as the famous comet Aucturn’s Tear once more soars through the solar system, yet this cycle, strange portals have begun opening on each planet the comet passes, and a powerful entity trapped on the other side of these gateways desperately calls for help. To the Pathfinder Society, this is a once-in-a-human-lifetime opportunity to discover what lies through these portals—and either free the captive trapped within or ensure that it remains sealed forever.