In the winter of 1927-28, the isolated coastal settlement of Innsmouth, Massachusetts was assaulted by U.S. government agents—its waterfront burned and dynamited, its people taken away to internment camps.

Yet that was neither the beginning nor the end of the horror uncovered by a young antiquarian who traveled to Innsmouth in search of rumors from the town's dead past, only to find them still very much alive...and find truths lying under water deeper and colder than any earthly grave!