Immersive Ink

Let's move forward into the elevator room (being careful not to step on the slush, but watchful for any treasure left behind in the residue) and proceed to the eastern door (purportedly somewhere behind which are giant scorpions). After listening and opening, if nothing is encountered Franklin can scout ahead (invisibly). The rest of us can keep watch.

Agreed.

You spend a bit of time cautiously poking through the slush, and are rewarded with three bright gems

You hear a faint rattling behind the door

Franklin slides on his ring of invisibility and volunteers to investigate the rattling noises. (This is the scorpion room now, correct?)

As you understand it, yes

Maloof remains on watchful guard (he is NOT close to the door when it is opened!)

"Hold Sconces back, please." The loyal pup whimpers with anxiety as his master vanishes into thin air! Franklin won't try anything brave or clever; just a quick assessment of the situation, then he'll report back to the team. Franklin readies his potion of swiftness instead of his weapon; from now on his standard operating procedure on these scouting missions will be to chug the potion and run away, if he gets in serious trouble.

The door opens onto a 40' square room (all of it to the east or south), but the ceiling is only 5 feet high. Along the middle of the north wall is a barred door, and rattling against it is a frantic giant scorpion

Franklin's first thought, "This is easy, we can just shoot the scorpion through the bars, and it won't be able to fight back." But the more he thinks about it, there must be some horrible catch. Maybe it's a trap, and the door is activated by a pressure plate (releasing the scorpion)? Without physically moving farther into the room, Franklin looks around to hopefully answer three questions:

1. Is the scorpion taller than 5'? Would it have a hard time fitting in this room with the low ceiling?

2. Does he think the scorpion's "frantic" behavior is directed at him? He waves his (invisible) arms to see if the scorpion reacts to his movement.

3. Does the barred door look like a normal door, with doorknob and hinges? Or is it more like a portcullis that would be raised by some mechanism?

If nothing bad has happened yet, then Franklin takes out his crowbar, reaches up and taps the 5' ceiling (to verify whether or not it's solid) then reaches down and similarly taps the floor.

1. Is the scorpion taller than 5'? Would it have a hard time fitting in this room with the low ceiling?

Even large scorpions are fairly flat, so it could fit. It could probably even use its sting

2. Does he think the scorpion's "frantic" behavior is directed at him? He waves his (invisible) arms to see if the scorpion reacts to his movement.

It does not react to his movement, but can probably sense him in other ways

3. Does the barred door look like a normal door, with doorknob and hinges? Or is it more like a portcullis that would be raised by some mechanism?

More like a portcullis

If nothing bad has happened yet, then Franklin takes out his crowbar, reaches up and taps the 5' ceiling (to verify whether or not it's solid) then reaches down and similarly taps the floor.

The ceiling and floor seem solid