×0. There are no secret walls anywhere in the room.

1. To beat the room, I have to kill the brain.

2. The only things capable of killing the brain are Beethro and the adders. The adders can't get to the brain, so Beethro has to kill it.

3. To get Beethro out again, I need to open the green door. So the seep needs to be dead before I kill the brain.

4. The adders can't kill the seep, and Beethro can't get to the seep, so the only way to kill the seep is by moving something onto the pressure plate. I then have to move it off the pressure plate in order to get to the brain.

5. The only things in the room that can depress a pressure plate are Beethro, the adders, and the mirror.

6a. If I use Beethro, he gets trapped by the force arrows and I can't complete the room.

6b. If I use an adder, its head will necessarily be above (and therefore remain above) the force arrows, so I will be unable to kill it and complete the room.

6c. If I use the mirror, I have no way of moving it off the pressure plate (or breaking it) without trapping Beethro. In particular, adders can't push or break mirrors.

×Remember that an adder shortens if at least one of the obstacles preventing it from moving is (itself or another) adder.

×It's true that the only things which can depress the pressure plate are Beethro, the mirror and the small adder. However, Beethro can't reach the plate without dropping the trapdoor, which locks away the brain for good. Beethro also can't push the mirror onto the plate without dropping the trapdoor. And nothing I can do will convince the small adder to go further north than the trapdoor itself, except sending Beethro across the trapdoor, which drops it.

×Monsters act as unbrained if the brain can't find a path to you.

×by placing the mirror in the narrow gap on the east side.