The sign on the wall is the quote from 'Alice's Adventures in Wonderland' by Lewis Carroll when the main heroine falls into the rabbit hole. The spiral structure of lettering symbolizes the rabbit hole itself.

`The rabbit-hole went straight on like a tunnel for some way, and then dipped suddenly down, so suddenly that Alice had not a moment to think about stopping herself before she found herself falling down a very deep well`

`Down, down, down. Would the fall never come to an end? “I wonder how many miles I’ve fallen by this time?” Alice said aloud. “I must be getting somewhere near the centre of the earth...`

`Let me see: that would be four thousand miles down, I think—” (for, you see, Alice had learnt several things of this sort in her lessons in the schoolroom)`