Ki and Gil will enter this room through that door at the top-left of it. It contains three Blue Knights, three Black Knights, one Mirror Knight, one Hyper Knight (which takes 306 hits to kill), one Red Knight (which takes 590 hits to kill), and one Green Lizardman too (which takes total of 402 hits to kill).
This room, like the left side of Water Line, wraps around vertically - and if you proceed in either direction, you will just end up back where you started.
The walls in this room spell out the word "KNIGHT" in the classic arcade font, which was first used by Namco's secondary US distributor Atari in their 1976racing game of Sprint 2. The key at the top of the room (up at the top-left of the "I") opens the aforementioned door at the left of the room, while the key at the bottom-left of the room (down at the centre of the "G"), opens the door at the bottom-right of the room. You should remember this now.
The aforementioned door at the bottom-left of the room leads back to Green Court (Room Pass: SC9) - and the door at the bottom-right of the room, like the one at the top-right of Undead Graveyard, leads to Junction (Room Pass: QCY). You should remember the second of these Room Passes...
