Second Visit

Last time he only reached 150-feet deep into the mine but this time he was determined to reach the end of the mine. He was 600-feet deep and finally saw the origin of the water that flowed inside the mine. Focusing the light he saw a door at the end of the wall. He gulped his saliva in his nervousness began biting his lips. Should he go in there? Before opening the door with his hands he knocked at the door. First came the small light knock and with no answer to be heard he knocked again with a little strength this time and even then there was no response. How stupid of him to think that somebody was behind that door? Or was he right?