"The Sandwin Compact" is a novelette written by August Derleth, first published in Weird Tales in November 1940. The story is narrated by Dave, who spends summers at his uncle Asa's house. Uncle Asa exhibits unusual behavior, such as responding oddly to the call of a sea-bird, which Eldon reveals was not a bird at all but something else communicating with Asa. Dave experiences strange dreams and finds the house smelling of fish and with phantom footsteps and vocal sounds. Upon investigating, they find Uncle Asa arguing with something that croaks in an unknown language and the room dripping and wet, leading to Uncle Asa's confession that the Sandwin family has been selling off its oldest sons to Cthulhuoid hordes for generations to maintain their wealth.
