Asensy Entrance
** SPOILER **

In the image above, the tiles which M.C. Presley refers to in his Rock-Around-The-Clock allegory are:
A) 9:00
B) 7:30
C) 6:00
D) 1:30
The idea is is that as you walk around the clock, different items will appear which you may pick up. These items are necessary in order to then acquire the skeleton key.
STEP 1: To begin the puzzle, walk onto position B. This shall reinitialize the puzzle. During the remainder of the puzzle, you will want to avoid stepping on B as that will reset everything. However if you ever mess up, you may step on B to start all over again.
STEP 2: Repeatedly loop around the bookcase by walking between points A and C. It does not matter which one you start on, but you must never walk on B during this step. So, to walk from C to A you must walk counterclockwise around the bookcase. To then walk from A to C, you must walk clockwise around the bookcase. Loop back and forth between A and C, and objects will appear around the bookcase which you may pick up during your back-and-forth walks. Continue looping back and forth until you have collected at least one specimen of each of these objects: unlit torch, ring of water breathing, stars, enchanted fruit, holywater flask, and bones.
STEP 3: Drop the following items onto D, in this order: Unlit torch, ring of water breathing, stars, enchanted fruit, holywater flask, and bones. With each item dropped, you should hear a "kablowee" sound effect. After all 6 items have been dropped, walk onto D (if you are already on D, then walk off of it and back on.) This will cause the skeleton keys to appear. You only need one key, but multiple keys are available in case you are playing in multiplayer mode.
STEP 4: Make sure to obey the sign posted to the right of the doors. You should now be able to enter Asensy.
WARNING: ACS has a limit on how many tiles may exist in the rooms. If you have followed the steps above but still have not been able to collect all 6 items necessary (or if the key doesn't appear,) then ACS may have reached its tile limit. To fix this, you can try removing any stray objects you may have left sitting around in the various rooms, by picking them up. Note that fruit and water can be removed permanently from your inventory by "use"ing them, allowing you to then pick up more fruit and water from the rooms. Stepping on B may also remove the items, but only if they are in the "Asensy Backdoor" room.
If you can not clear enough objects from the rooms to break out of ACS' tile limit, the best solution is to start a new game with a fresh copy of the game. This is the very first puzzle in the game, so not much playtime will be lost.