Grimrock

I seem to be completely stuck in Castle Nex in a room with a moving skybridge and another single tile skybridge sealing a hole in the floor. There's two ladders behind me that lead to a door I can't open and I can't get onto the moving skybridge. What am I missing?

Try to go down instead of up...

Look around for any pressure plates blocked by a gate you can drop an item through.

That room had me stumped too.

As Belligero stated look for the one area you can drop something through.

Ah right, thanks everyone, I could see the portcullis but didn't notice there was a pressure plate below it.