Travel writer Dirk Barnevelt and lecturer George Tangaloa, associates of interplanetary explorer and documentarian Igor Shtain, are drafted on Shtain's disappearance to complete his commission to explore the Sargasso Sea-like Sunqar area of Krishna's Banjao Sea — and incidentally to find Shtain, who is suspected to have been kidnapped to Krishna. Arriving on the planet, the Earthmen travel to their goal in disguise as native Krishnans; Barnevelt himself is given the alias of the famous general, Snyol of Plesht, from the Antarctic nation of Nichnyamadze (setting of the Krishnan short story "Calories"). Snyol's formidable reputation proves at various times both a boon and a hindrance to their mission.