What Lovecraft story features the character Harley Warren?

“What Lovecraft story features the character Harley Warren?” — “The Statement of Randolph Carter.” Harley Warren is the occultist companion whose disappearance drives the story’s plot. Randolph Carter gives the tale as a statement after being found wandering in a shocked, confused condition.

Warren has discovered a mysterious book and believes that hidden passages lead beneath an old graveyard near Florida’s Big Cypress Swamp. He descends into a tomb while Carter remains above, connected to him by telephone wire. Warren’s increasingly terrified messages end with a warning that Carter must flee, followed by a voice claiming that Warren is dead.

The story was inspired by a dream Lovecraft had and was written in 1919. It is also important because Randolph Carter became one of Lovecraft’s recurring protagonists. A common mix-up is to associate Warren with “The Silver Key” or “The Unnamable,” which also involve Carter or related supernatural themes, but neither is the story in which Warren vanishes underground.