sentences:  In this sequel to "Crater 101", Spectrum uses the crystal taken from the Mysteron outpost on the Moon to contact the enemy and propose a truce between Earth and Mars.Following the destruction of the Mysteron outpost on the Moon, Dr Kurnitz of the Nash Institute of Technology has discovered that the crystal removed by Spectrum can be used to communicate with the Mysterons on Mars.Captain Scarlet (voiced by Francis Matthews) escorts Kurnitz to Cloudbase, where an interplanetary transmitter has been constructed.