I was exasperated, but I stayed.

In the afternoon the minister came with two strangers to visit the school.

I went through my lessons with dignified inaccuracy, and was commended.
Going back, I happened to step on a loose board under my seat.

I determined to punish Mrs.Desire for the undeserved praise I had just received, and pushed the board till it clattered and made a dust.
When Mrs.Desire detected me she turned white with anger.

I pushed it again, making so much noise that the visitors turned to see the cause.
She shook her head in my direction, and I knew what was in store, as we had been at enmity a long time, and she only waited for a decisive piece of mischief on my part.