The corridor ahead of you is 20′ wide and 200′ long. A 5′ stone path goes down the center, and the the rest seems to be some kind of molten material. The corridor is actually only 10′ x 100′ and has had a Distance Distortion spell cast upon it, so that only True Seeing will reveal it, although it does radiate a dim dweomer. Every 10′, there are gaps in the real path – these appear every 20′ in the distortion. Characters walking down the path must make a Saving Throw vs. Death Magic every other 10′ or fall into the gap, taking 6d6 damage.