The FF take a much needed vacation! But while the happy family sunbathes in Florida, a mysterious fish-man is on the loose. Plus, will Reed Richards find the Lost Lagoon of mythic lore?
This story appears to have been inspired by the 1954 science-fiction cult classic film, "The Creature From the Black Lagoon". However, the sequel story in Fantastic Four #124-# 125 is even more reminiscent of the 1954 film than this story, due to the kidnapping of Sue Storm, similar to the abduction of actress Julie Adams in the 1954 film.
The story begins with the Fantastic Four taking a vacation in the Lost Lagoon, while at the same time investigating the sinking of some ships in the area, at the request of the U.S. Navy. A whale creates a huge wave for the Navy's Air-Sea Cruiser that Mr. Fantastic has burrowed for the FF's investigation, but Reed Richards tells Johnny Storm and Ben Grimm that the whale could not be responsible for the ships being sunk, as witnesses have reported seeing a monster in human form. Later, at the beach, the gals go crazy over Johnny, while Reed and Sue share a tender kiss, as the Monster secretly watches them in the background.
We soon see the Monster in his underwater cave and he uses a machine to change into human form and then he goes to a nearby Oceanarium to hide his identity. Watching the human-form Monster so at home with the dolphins in the Oceanarium, Reed gets suspicious. He stretches his arm deep into the water and this angers the Monster and he throws a pilot whale at Mr. Fantastic's arm like a torpedo. When the Monster gets out of the water, Reed asks him to be their guide as they explore caves in the area. Soon they are underwater in the Navy's Cruiser and the human-form Monster punches his way out of the Cruiser, causing it to sink to the bottom. Luckily, the quick thinking Reed Richards uses a spear gun to effect an escape into a cave above the water line. They suddenly now see the Monster in his true form. The Thing and the Monster fight it out, but it is the Torch's flame that scares the Monster away. Chasing after the Monster, the three male members of the Fantastic Four see a space ship and they now realize that the creature is an alien. He is loading plastic bags filled with water onto his ship and the FF also see that he has a female of his species aboard the ship, presumably his mate. The ship suddenly takes off and the Thing's closing line certainly causes one to recall the 1954 science-fiction film, "If they ever make this into a movie..this'll be the perfect spot fer a fade out!"