Start in the secret grate room in the clocktower so that you are not bombarded by medusa heads
Have the AXE subweapon ready and walk out the doorway. Dont move out of the doorway, jump up and throw the axe. The axe will hit the gear above your head and thus closing the door on you
The screen will flicker for a brief second and you will end up falling to the floor.
Turn to bat or mist and fly up along the edge of the room