Based on the H.P. Lovecraft short story, The Whisperer in Darkness. A local hermit, Henry Akeley, discovers a race of aliens living in the rural Massachusetts mountains. After a historic flood, reports of strange bodies floating in local rivers catches the attention of mythology professor, Albert Wilmarth. His curiosity leads him to meet Akeley under strange circumstances. With repeated attacks by the aliens and Akeley's increasing insanity, it is brought to a horrible climax.