After take-off, Soviet cosmonaut Akilina 'Leena' Chirikov finds herself thrown into another dimension, a world of strange science and ancient mystery. There she meets another time-lost person from Earth, Lieutenant Hieronymus Bonaventure of the Royal Navy - who left home to fight the forces of Napoleon and never returned - and Balam, outlaw prince of the jaguar men. They agree to help Chirikov find a way home.