In the summer of 1974, in a derelict Rhode Island mansion called Trevor Hall, a team of scientists taught American Sign Language to a chimpanzee. They affectionately christened their subject "Smithy." His official name was Webster.

The Smithy Project ended in tragedy, some believing that a dark presence inside Trevor Hall had been disturbed. Webster was acquired by CSAM, a research lab in California run by the iron-fisted Manfred Teague. CSAM had a reputation for sullen staff, gloomy conditions, and cruel experiments. Despite this, two of Webster's original researchers, Jeff Dalton and Ruby Cardini, followed him west, determined to look after their friend.

But another entity followed the chimp as well, and in the waning years of the 1970s, "Webster" became synonymous with a menagerie of inexplicable events, strange social movements, curious legal cases, and chilling courtroom testimonies. All were haunted by the question left unanswered at Trevor Hall: Had Webster not only bridged the gap between man and animal, but between this world and the next?