After human astronauts attack their city on Mars due to a misunderstanding, the vengeful Mysterons declare war on Earth,[e 1] initiating a series of reprisals that are countered by Spectrum, a worldwide security organisation. Spectrum boasts the extraordinary abilities of its primary agent, Captain Scarlet. During the events of the pilot episode, Scarlet acquires the Mysteron healing factor of "retro-metabolism" and is thereafter considered to be virtually "indestructible", being able to recover fully from injuries that would normally be fatal.[e 2]