This is the forum for helping you out if you're stuck or if you want to discuss the nitty gritty details of the dungeons within Mount Grimrock. Warning: forum contains spoilers!
There's a teleport on level 5. Has anyone been through it?
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It's the one where you throw the rock to open the gate. I think it might have something to do with those items nearby behind the grate, with the button inside.
If its the teleport I think it is, its to remove the items on the plate to reset the puzzle. After you complete the puzzle and clear the area, you open up a route back to the main area as you get closed off after the puzzle "there is no turning back" written on the wall.
The same lever opens the gate with the items behind it, the button in that room just opens the gate up again (as its also timed)