Masters, the Permanent Under-Secretary in charge of the centre, arrives. The Doctor tells them about the Silurians in the caves, urging peaceful contact. However, this is ignored when Quinn's assistant reveals that he was killed by the Silurian he held captive. The Doctor attempts to warn the Silurians, but they put him in a cage. The older Silurian tells the Doctor how their race retreated underground when they saw the Moon approaching Earth millions of years ago. The hibernation mechanism malfunctioned, and they did not revive until a new power source was discovered. A young Silurian orders Baker infected with bacteria before he is released. The older Silurian releases the Doctor, giving him a canister of the bacteria so he can discover a cure. The younger Silurian usurps and kills the older one for this act, becoming the new leader. The Doctor reaches the centre and warns everyone to stay away from Baker, who collapses with the infection. Masters decides to return to London, unaware that he has been infected. Baker is taken to a local hospital and dies.