The Slytherin common room was dark; he could barely seeing the furniture as he tried not to bump into them. Regulus reached the corridor quickly, hoping that his friends did as agreed and none of them were caught.
Unfortunately there was not any staircase which led him to the fifth floor directly, because it was built on the highest part of the land of Hogwarts. The stairs to access it was placed on the third floor, on the opposite side of the school. He hurriedly walked through the long corridor, taking care to go unnoticed. However, when he reached the third floor, Regulus spotted the Slytherin Prefect - Rosier - who was going the same way. For not knowing how the prefect would judge him, he waited in the shadows for few moments until Rosier vanish upstairs. This time was enough for Theodor to reach him:
'What happened, Reg?' He whispered into Regulus' ear, who was awfully frightened by the sudden arrival of his friend. He had to stifle a scream with his hands.
'Ah, it's you! It's nothing, I just saw Rosier ahead. As I don't know if he is in agreement with the club, I thought it best to wait. Now let's go!' He replied in lower voice.
The two boys were climbing the stairs when Jack and John overtook them, panting.
'I think we saw Peeves, hurry up!' Said John.
Then the four friends rushed up the stairs, coming quickly on the 5th floor. They were walking when Severus came out of the shadows behind a suit of armour:
'I see you've invited your friends, Black.' Severus said, with surprise and disappointment at the same time.
Regulus responded by shrugging his shoulders, a bit embarrassed. Will Severus want to duel him? But before he could think about it, Snape whispered:
'Come on, here. Don't make noise.'
Snape led them to the end of the hallway, entering behind the pendulum clock. On the ceiling was a trap door. Then he took out his wand and cast a spell that left the trap door momentarily pink. Then someone opened the trap door inside and down a wooden ladder. He walked backwards to give space for the ladder and said:
'Let's go up.' He muttered.
Severus and the boys climbed the ladder. They reached which would be the back of the tower clock face, the one, who had handed down the stairs, vanished by a narrow corridor and walked through a door that was the end of it. After the last kid was up, they lifted the ladder and closed the trap door, care not to make any noise, which did not make much sense because the machine's tower clock already made enough noise to disguise others.
They followed the narrow corridor after Snape, who knocked seven times as who drew the number seven on the surface of the door: four knocking to the right, three descending knocking slightly to the left. Then it opened up to a small lobby where there was a spiral staircase. Regulus looked downstairs, but could see nothing, because the stairs were too dark and really extensive.