GET OUT

[Lucy]

You pick up the pencil and write "free button" with an arrow pointing to the bomb.

Well now you've created a situation in which the bomb could go off at any time. Rookie mistake.
 

They fall to and through the floor as you put your weight on them, again.

Can you take one of the empty boxes, flatten it out, and slide it underneath one of the shelves to prevent it from passing through the floor?

You ponder your folly. You'll accept the risk of being blown to smithereens if it means there's someone else here.

You empty out one of the boxes and fold it flat, and put it underneath the shelves where they vanish into the floor. Stepping on the shelves once more, you hear a soft crunch of folding cardboard. It's simply not strong enough to hold your weight. And it has taken the box with it into the void. You inspect this further, it's not literally phasing into the floor, there's a hole there where the shelves fall into it and past the floor. There's about 2mm of clearance between the shelves and the floor, a tight fit. You reach in and try and grab your box back, it's not there, fallen through entirely. Whoops.

You think this was a good idea though, and ponder what else you have that might be able to wedge the shelves in place while being strong enough to hold your weight. The axe's handle perhaps? You really don't want to lose the axe though.

What is to be done?