Volunteering for the mission, Captain Scarlet, Captain Blue and Lieutenant Green (voiced by Francis Matthews, Ed Bishop and Cy Grant) travel to Lunarville 6, where they are briefed by Controller Linda Nolan and her colleague Shroeder before departing for Crater 101 in a Moonmobile. Reaching the crater, they transfer to a Lunar Tractor. Automated sentry vehicles move to attack them but are immobilised when Green destroys the control vehicle with the tractor's rocket launcher. Donning space suits and entering the complex, they discover the power source to be a pulsating crystal embedded in machinery. However, unknown to the Spectrum officers, the Mysterons have killed and reconstructed Frazer, a Lunarville 6 colonist who has transported the atomic device to Crater 101 by Lunar Tank. Frazer has rigged the device to detonate two hours early to ensure the failure of the mission.