Soviet engineer Los travels to Mars with assistant Gusev. There, Los finds that society is separated like old forms of capitalism with strong contrasts of the powerful and the poor. THe leader, Toscoob, claims that their city must be destroyed in the wake of Mars' failure, since an environmental catastrophe is on the brink. Gusev becomes a leader of the rebellion, which fails, and after falling in love with Aelita, Los and Gusev make it back to Earth. Due to time dilation, it is ambiguous as to the fate of Mars and Aelita, but radio transmissions make it believable that Aelita is still alive.