There is a loud creak as you put your weight on the first step. Unless you want to get the attention of every goblin hunting party in the area you'll have to climb slowly. Once you clear the top of the entryway everything's much darker. You're feeling your way around blind, shifting your weight methodically.
You're near the top of the tall tower when your foot passes through a completely rotten step. You swing your arms for anything to grab but there's nothing but air. You go crashing down to the stone rubble below.
They say your life flashes before your eyes when you're dying, but that just isn't the case. There is only a moment of panic followed by nothing at all.