His belief is based on another strange recent occurrence in the Pacific: "Lagrange fireballs", spheres of energy which move in a seemingly intelligent manner and appear to be responsible for the disappearance of people in Hawaii.
While one of the scientists is on deck preparing to ride up the water column in a bathysphere, an energy sphere appears; it engulfs him, and he disappears.
The other scientist, still believing that there is an intelligence behind these phenomena, decides to take the other's place and ride in the bathysphere up the water column in hopes of finding his colleague and/or further insight.
The two men find themselves in an utterly featureless (and inescapable) environment where they are provided solely with bland food and water.
Floyd C. Gale of Galaxy Science Fiction praised "Goldfish Bowl" as one of the "up-to-the-minute masterworks" of The Menace from Earth.