The character was thinking about death, he was scared, nervous, and death was on his mind.
What Does He Think?
In the story "The Pit and the Pendulum" by Edgar Allan Poe, The character feels around the cell trying to figure out where he is and how big the cell is.
What Does He Do?
We don't know much about the character other than hes locked in a cell and sentenced to death. He's a bit unstable, but when you are put in this situation, who wouldn't be? He's a philosopher which allows him to think deeply about the situation which helps him through different obstacles throughout the story. The first bit of information that we get is that he is disoriented. We have no idea what his name is or what the crime he has done to be put in there.