This is the first room in the game to be divided into three sections. Ki and Gil will enter the left section through either thAT door at the top-left of it (if they came from Water Line), or the door at the top of it (if they came from Party Room), which contains no enemies at all (unless the Will O' Wisps).
The key at the bottom-left of the left section opens the aforementioned door at the top-left of the left section, the key at the bottom of the left section opens the door up at the top of the left section, and the key at the bottom-right of the left section opens the door up at the top-right of the left section.
The aforementioned door at the top-left of the left section leads back to Water Line (Room Pass: YF7), the aforementioned door at the top of the left section leads back to Party Room (Room Pass: SC2) - and door at the top-right of the left section leads to the centre section (Room Pass: still HC2).
If Ki and Gil went through the door at the top-right of the left section, they will re-enter through the door up at the top-left of the centre section, which contains four Blue Captain Knights (which take fifty hits to kill and have green eyes) and eight Black Knights (which only take twenty-two hits to kill).
The key at the bottom-left of the centre section opens the door at the top-left of the centre section, and the key at the bottom-right of the centre section opens the door at the top-right of it.
The aforementioned door at the top-left of the centre section leads back to the left section - and door at the top-right of the centre section leads to the right section (Room Pass: still HC2).
If Ki and Gil went through the door at the top-right of the centre section, they will re-enter through the door at the top-left of the right section, which, like the left, contains no enemies at all.
The key at the bottom-left of the right section opens that aforementioned door at the top-left of the left section, the key at the bottom of the right section opens the door up at the top of the right section, and that key at the bottom-right of the right section opens the door up at the top-right of the right section. You should remember all this for when you actually reach the room.
The aforementioned door at the top-left of the right section leads back to the centre section (Room Pass: still HC2), that door at the top of the right section, like the one at the top of Small Dome, leads to Training Yard (Room Pass: 937), and the door at the top-right of the right section, like the one up at the top-right of Dining Room, leads to Green Court (Room Pass: SC9).
