You jump down, breaking your leg and blowing out and losing your candle in the process.
If only you'd descended carefully!

There is a small shaft of light far to your left at the top of an unseen wall, and a small hole in the wall next to you on your right. Whatever the unseen creature is, it's clearly large, unfriendly, and alerted to your presence, so there's probably only time to investigate one.

Do you:
examine the small hole,
drag yourself to the shaft of light,
or stay here and try not to make a sound?