The sonic blast triggered by Zondal glances the base, causing minor damage. Varga uses the communicator to call Clent, threatening to fire again unless the humans surrender. Clent knows the base dome cannot survive another sonic blast and suggests a peace meeting between the two sides. The talks fail when a demented technician, Walters, tries to shoot the Martians. Varga dismantles the Ioniser reactor to get the mercury isotopes he needs for his ship. Without the ioniser, the glaciers move forward.