It was possible that my conjectures were erroneous.
The door of his room was locked.

I knocked; I demanded entrance in a low voice; I put my eye and my ear to the keyhole and the crevices; nothing could be heard or seen.

It was unavoidable to conclude that no one was within; yet the effluvia of gunpowder was perceptible.
Perhaps the room above had been the scene of this catastrophe.

I ascended the second flight of stairs.

I approached the door.