The Maw by Steven Utley (F&SF, July 1977) opens in Jack-the-Ripper territory:
He came on the midnight air, a mist-man, a wraith stretched across the centuries, a shadow two hundred years removed from the flesh that cast it, a wisp of smoky gray nothingness drifting down out of the sky, settling to earth in the darkness of an alley between two decrepit houses. Behind him in the alley, an emaciated mongrel dog sensed his almost-presence and backed away, growling. He stared at it for a moment, his eyes twin patches of oily blackness floating on a face that was only a filmy blob, then pressed his hands against sooty bricks and dug very nearly insubstantial fingers into cracks in the mortar. Time let him go at last, surrendered its hold on him, gave him over completely to the moment that was 11:58.09 p.m., Thursday, November 8, 1888. p. 110
The mist-man drifts about the city (we get bits of local colour and Jack-the-Ripper lore) until (spoiler) he arrives at the scene of the Ripper’s last victim. There, the mist-man waits. When Jack and the victim arrive, and he is just about to kill her, the mist-man descends from the ceiling and enters him. The mist-man explains to Jack that he isn’t killing the women for the reasons he thinks he is, but to feed a maw that stretches across people and time.
After Jack finishes butchering the woman (which is described in grisly detail) he leaves, and the last section has him remonstrate with the mist-man for revealing the true reason for his bloodlust. The mist-man says to him, in a biter-bit line, “It was terribly cruel of me, wasn’t it, Jack?”
This piece is more of an atmospheric history lesson than a story, but it it’s an absorbing piece nonetheless.
*** (Good). 2,850 words.