The story opens with a precise, almost clinical observation: 'Simon Grue found a two-inch mermaid in his bathtub.' This sentence immediately establishes the blend of the mundane and the fantastic that characterizes the entire work. The narrative then moves outward from this domestic discovery to the roof next door, where Russian neighbors have set up a mysterious apparatus involving a water tank and pipes. Leiber uses the physical layout of Greenwich Village—the studio window, the stepladder, the tarpapered roof—to create a geography of curiosity. The recurring image of the pipe, described as 'a giant umbilicus or a canal for a monstrous multiple birth,' anchors the story's movement between the real and the imagined.

A Roof with a History

The roof next door is not merely a setting but a layered artifact. Leiber catalogs its previous occupants—a bootlegger with a pipe organ, Buddhist monks, a commedia dell'arte troupe, Swedish blondes breeding 'sinister smoke-colored dogs'—each leaving a trace. This inventory establishes a pattern of transformation: the water tank once stored hooch, later held the monks' vegetables, and now contains the Russians' experimental creatures. The roof becomes a stage where the past echoes into the present. Simon's view from his studio window, requiring him to 'stand halfway up a stepladder and peer,' physically enacts the act of looking into another world. The Russians themselves are introduced through a series of contradictory labels—White, Red, 'both Red and White and something more'—suggesting that categories fail to contain them.

The Scientist's Dilemma

Vasily Stulnikov-Gurevich, the brother who conducts the experiments, articulates the central conflict in a speech punctuated by thunder. His research has produced 'little swimmers'—creatures that are part tadpole, part mermaid, and disturbingly reminiscent of his sister Grushenka. Vasily describes the reactions of his brothers: Lev sees money, Ivan sees political weapons, Mikhail sees 'unshriven souls.' The sister herself has retreated to the bathtub, silent and transformed. Vasily's language shifts between scientific detachment ('pure research, the play of the mind') and moral anguish ('works of evil end in the whirlwind'). The thunder that accompanies his confession is not mere atmosphere; it becomes part of the narrative's rhythm, with Simon perceiving 'music in it' as his own visions intensify.

Visions in the Pipe

As Simon sits beneath the pipe connecting the water tank to the pent-shack, his perceptions blur. The 'semi-transparent shapes of the polliwogs' in the pipe above him become 'hordes of swimming pygmy souls' in his mind. Leiber traces a precise progression: from tadpoles to 'unborn water babies' to 'miniature mermaids' with 'bright smiling lips and eyes, long Lorelei-hair.' The transformations are not merely visual; they carry a hypnotic quality, described as 'hypnotic vibrations' that induce 'dreams of the piquant sort.' Simon discovers that the creatures' faces bear 'a transcendent resemblance' to Grushenka's, a detail that ties the scientific experiment to personal obsession. The pipe itself becomes a conduit for multiple meanings—biological, erotic, metaphysical—as Simon imagines it as 'a giant umbilicus or a canal for a monstrous multiple birth.'

Movement Between Worlds

The story's structure depends on a series of vertical and horizontal movements: from the bathtub to the roof, from the studio window to the water tank, from the real to the visionary. Simon's position on the stepladder, halfway between floor and skylight, mirrors his liminal state. The thunderstorm that builds throughout Vasily's confession creates a sensory bridge between the mundane (a storm in New York) and the fantastic (the 'whirlwind' Mikhail warned of). Leiber uses the physical details of the setting—the pipe, the water tank, the chicken-wire enclosures—as anchors that keep the story grounded even as it veers into surrealism. The reader, like Simon, is never allowed to forget the material reality of the roof, the tank, the pipe, even as the visions become more vivid and the boundaries between self and other dissolve.

Readers should attend to how Leiber uses the physical environment—the studio, the roof, the pipe—as both a stage and a source of meaning. The story's power lies not in its fantastic premise but in the precise, almost documentary way it renders the ordinary details of Greenwich Village life, then gradually infuses them with strangeness. The pipe, the water tank, the bathtub: these are not just props but active participants in the narrative, conduits for transformation. Pay attention to the way the storm builds in parallel with Simon's visions, and how the brothers' conflicting interpretations of the experiment—as science, commerce, politics, or sin—remain unresolved, leaving the reader suspended between explanations.