A row-boat carrying a butchered man washes ashore in Montaba, India. The man has no ears, no tongue, and his heart has been ripped out of his chest. Chief Investigator Juan Anthony somehow recognizes the body as Morris and vows to get to the bottom of this.
Morris had been looking for information on the High Priestess Vishnaw who was thought to be living on the titular Isle del Monstruos. Anthony reaches into Morris’s loin-cloth and finds a book. Dude, use a rolled up sock like everyone else!
Morris wrote that he witnessed the horrible Dance of Fertilization. Doesn’t really sound that horrible. Unless it was like that time when I woke up one night and saw Tony banging Carmela on the Sopranos. Yeah, that was kind of horrible.
He reads Morris’s description of Vishnaw. The legendary Indian deity is naturally described as “caucasian . . . flaming red hair.” Anthony and his sidekick Hack Larson row to the island to get the scoop.
The search gets off to a good start — after the three hours of back-breaking rowing, I mean. Their boat is suddenly surrounded by naked blonde babes in the water. The girls with their “firmly molded breasts” make the men’s dingy move like they were motor-boating. They are propelled to the shore.
They continue rowing into a subterranean river where they hear a “groan . . . a low, sobbing sound,” then the sound suddenly stops — sure sounds like a Fertilization Dance to me. They see a set of stairs carved into the stone and tie up the boat. The moaner was a bloody man now laying dead on a raised alter. The tall blonde High Priestess has cut off his ears and ripped out his heart as “20-30 of her nearly naked disciples” look on with 40-60 bare breasts. Within seconds, Anthony and Hack are captured.
Anthony awakens and is surrounded by vestal virgins. He is hailed as the returned Great White God Vishnaw, and is being prepped for a union with the beautiful High Priestess. After having lots of the sex, Anthony understandably dozes off. Only after he wakes up does he remember, oh yeah, wasn’t there another dude with me? Yeah, the poor sap I saw dragged into a pit by some long hairy arms. Anyhoo, wonder where that High Priestess babe got to?
In the darkness, Anthony sees something creeping toward him. “A huge, hairy body with welts across its shoulders slithered toward the divan. Two great eyes like balls of fire gleamed evilly from its glistening skull. It left a slimy trail behind it like some enormous slug emerging from the bowels of the earth.”
As the thing gets between Anthony and the High Priestess’s “firm breasts, slowly rising and falling abdomen . . . the slimly tapering heads and legs,” he jumps on and starts a-wrasslin’. Once again, he is knocked unconscious.
When he wakes up this time, he is not surrounded by blonde virgins, but six or eight ghastly beasts; well, they’re probably also virgins. The things are chowing down on the dead man he saw earlier.
Anthony escapes and finds his gun. He witnesses Hack being brought in as the next sacrifice. Anthony goes all Travis Bickle and rescues Hack from being de-eared, de-tongued, and de-hearted. They row away from the island after leaving a massive explosive charge. This story is so old, it was probably C-1. 
A fairly mediocre offering from this collection.
-  The first C-4 was just called C and developed in WWII.
- First published in August 1935.
- Also that month: Will Rogers killed in plane crash.
- Isle of Lucy