1 Eleven: So what’s the correct way out of this room?
2 Lucas: The black circle on this wall should be an illusion covering the crawlway to the Chapel of Evil.
3 Lucas: {upper half invisible behind the black portal} Yeah, the passage is here.
3 Eleven: You’re very trusting that looking in there would be safe.
4 Lucas: Any nerd who went to the trouble to reproduce the Tomb of Horrors would be peeved if they didn’t get it exactly right.

I had a bit of a problem staging these shots. The background image of the wall (taken from the illustration pack in the adventure module) doesn't extend any further to the right than shown here, and I needed to cram the characters into the small amount of available space on that side. So that's why Eleven is cut off in panel 3 and we can only barely see Dustin in panel 4 (and not at all in 2 and 3).