 Captain Black mistakes a Mysteron camera for a cannon, which I understand since it looks like one, and attacks a Mysteron complex. The Mysterons misunderstand and start a war of nerves, putting Captain Black under their control. They threaten to kill the World President. Captain Scarlet and Brown are killed and reconstructed by the Mysterons. The first attempt fails, and during the second attempt Colonel White discovers that the Captain Brown that escorted the president wasn t really Captain Brown, and that Captain Scarlet is under the control of the Mysterons as well. This means the President is in danger.