Oakey came back to the 5th floor and looked at the door... Why did Vindictus want to get in this room? Why couldn't he?

He walked over to it and tugged at the handle. It didn't open...he tried again, and again, and again...nothing. He put one foot on the door and pulled with all his might to open it. He was even able to get both feet on the door while furiously tugging at the door to open.

He fell flat on his butt soon after. Catching his breath Oakey starred at the door for a little while longer. maybe it opens the other way? Oakey thought.

He pushed it lightly and nothing happened. then harder, and harder again. Until he was pushing at the door so hard it felt like he was trying to move an elephant. He stopped at this as well and sat on the corridor floor catching his breath, starring at the Mystery Door.