This lasted for several years, but the continued efforts of C-Consciousness were unable to repair the damage they had done to the Zone. In fact, the damage appeared to be getting worse, with "Blowouts" deepening the distortion of the noosphere around the Zone at irregular intervals. Still, the C-Consciousness entity persisted in its experiments, behind the shields of the Monolith and the Wish Granter myth, the Monolith faction's patrols, the Brain Scorcher, and the dangers of the Zone itself. Occasionally, though, special circumstances would require an agent, a human able to do what was needed to preserve the Zone's secrets without revealing the existence of the C-Consciousness project. In these cases, Stalkers who were tough and resourceful enough to make it to or past the Brain Scorcher would be captured, brainwashed, and sent back into the outer areas of the zone on one of the "Death Trucks." These agents were marked with the tattoo "S.T.A.L.K.E.R." This is where Strelok, the main character, enters the story.