Rise of the Undead Legion Chapter 129 No pancakes for you Alfie

Dave left the trap room and made for the fourth door.
He found himself in a room with some levers on the wall to his right..
He walked through the door into a square room, bare of anything except for seven levers lining the wall. Each lever had a different colored handle.
He noticed there was a seam in one of the walls.
"That should be where the crimson box is hidden, it looks like the hidden doors in all of the other rooms."
He turned to inspect every inch of the room. He pressed on the walls, checked the floor, looked at the ceiling, but didn't find anything worth of note besides the seven colored levers.
He took some time to ponder before touching anything.
He noticed the handles were actually the seven colors of a rainbow, but out of sequence.
Then he pulled down on the red lever which was the middle one.
The moment he did, he heard a loud sound.
"Dooooo"
It was like a bell.
The lever stayed down and nothing else in the room changed.
Dave frowned.
"I think the door will open with the right sequence of levers."
He put his hand on the the orange lever and pulled down.
"Tiiiiii"
After the sound ended, the two levers returned back up to their original position and there was a vibration coming from above, Dave looked up, the whole ceiling was rumbling, slowly moving down, then it stopped abruptly.
So, too many unsuccessful attempts to solve the puzzle would mean the ceiling would slowly descend and crush him.
"No way Alfie. No Dave-pancakes for you today."
Dave pulled the red lever again and the same tone repeated, sounding through the room. No rumbling came from the ceiling, though he glanced up just to make sure. Then around the room to see if anything else was going to try ruin his day, like land-sharks.
"Okay, nothing happened except for the sound. I think that means the red lever is first in the sequence."
He tried another lever at random, it made a different sound.
It was like a horn blowing.
"Faaaaaa"
"Musical notes!" He laughed, almost certain he'd figured out how to solve it.
Then both levers flipped back to the up position and the ceiling rumbled down another few inches.
Dave pulled the red lever again, "Dooooooooo," and then picked a new color to try and pulled that lever down.
"Re"
"I was right!"
He tried the rest of the colors, pulling down the levers and hearing each one's sound. He memorized the note for each color. The ceiling was only a few inches above his head by then.
He tried the first simple idea that popped into his head. It's not like he would be expected to play Chopin or Mozart right?
"Do, re, mi, fa, so, la, ti."
The room trembled and the ceiling that came almost half the way down shook and retreated back to its original position.
The door at the end of the room shook for a bit and opened down the middle then stopped.
But it was only a few inches.
Dave went to the door, but couldn't see anything through the crack.
He returned to the levers and pulled the red one again.
The same note, "do," note sounded, but this time the ceiling rolled down toward hime and the lever moved back to the up position.
"The sequence changed. This is so random!" Dave became frustrated.
He stroked his beard looking at the levers, trying to come up with an idea.
He moved back to the wall and pulled on the green lever, it made the sound, 'ti'.
The lever remained down and the ceiling didn't stayed up.
Then Dave pulled the 'La' note lever and the ceiling still stayed in place.
"So. The correct sequence is in reverse now," Dave smiled, having figured out the second part of the puzzle.
He pulled the levers in reverse order and the halves of the stone wall finished pulling all the way apart, revealing what was behind them.
A wooden door painted red, there was a brass lock-plate with a keyhole in it at waist height.
Dave's expression was gloomy, "Another door. Great."
Dave felt the room vibrate, and the levers retracted into the wall.
He looked up to see the ceiling slowly descending with not the slightest sign it was going to stop.
"Fuck!"
Dave rushed to the red door, but he didn't have any idea how to open it. He didn't have a key.
"Key, key key! Where is the key!" he babbled, stressed.
There was no indication to the whereabouts of the key! There was only the stupid locked door before him.
He tried to push it open.
"Damn!"
The ceiling was only a dozen feet above Dave and dust was filtering down.
Then he saw some tiny marks on the door, writing! A message. A CLUE!
"What's this say?" his eyes almost crossed as he attempted to read the miniscule script, "The key is lost, what hinders you is a lock, your only hope is simply to…" and the writing ended there as if the last part was scrubbed out.
"What the hells is that supposed to mean! There's no fucking key!"
He looked up, the ceiling was only six feet above him. With an irritated expression he said, "I give up."
Then he went to the door he entered through, intending to leave the deathtrap.
Just before he got to the door, a wall came down, shutting off access.
Dave's face paled, "You gotta be fucking kidding me! Alfred, you piece of shitty code, you're really trying to kill me off, aren't you?" He was screaming when he finished his face red and his eyes bloodshot.
He sat down where he was and waited for the ceiling to come down, even the log-out option was grayed out.
As the ceiling continued its inevitable course Dave took a deep breath and relaxed. There was no point fighting it anymore.
"I guess this is it for Mr. Skeletal," he said mournfully.
"But what the hell is with this puzzle?" The damned puzzle clue kept running through the very back of his mind. The little rhyme or whatever it was.
The key is lost, what hinders you is a lock, your only hope is simply to…
"Simply to do...what? Hang on, it's a riddle. So the missing word has to rhyme, what is a simple thing to do when the door is locked...?"
He smacked his forehead, "No way! It can't be that easy?!"
The ceiling was only a few feet from his head as he sat in front of the door, it was so low he wouldn't be able to stand up straight now.
He had to crawl from the entrance door, he probably looked like a demented cat rushing for the red door on all fours.
"The key is lost, what hinders you is a lock, your only hope is simply to...KNOCK!"
Dave knocked alright. He hit the door continuously, desperately with his fist.
"Please let this work!"
The room shuddered as he started to beat on the doorand the ceiling stopped.
By that time Dave's face was almost down against the floor, the hard stone ceiling pressing down on him.
The ceiling started rising and he finally took a deep breath of sweet relief.
The door opened as if inviting Dave in.
Dave stood up and wanted to go in, but a thought crossed his mind.
"Who opened the door?"