The Venusians are gone, but their machines remain functioning, including the radiation-bombardment machine intended for use against the Earth. One of the scientists accidentally triggers the weapon, leading to a frantic effort by the team to disarm it. Tchen Yu lowers Talua, the ship's communication officer, into the Venusian command center. When Tchen Yu's spacesuit is punctured, Brinkman ventures out to save him. Before he can reach Yu, Talua succeeds in reversing the weapon. Unfortunately, this also reverses Venus' gravitational field, flinging "Cosmostrator" out into space. Brinkman is also repelled off-planet, beyond the reach of the spaceship, while Talua and Tchen Yu remain marooned on the devastated Venus. The surviving crew must return to Earth, where they warn humanity about the dangers of atomic weapons.