He slowly sat down again in the same place in the corner of the sofa, and shut his eyes as though from weariness.

The corner of the letter was still peeping from under the paperweight, but he didn't even move to cover it.
He soon sank into complete forgetfulness.
When Pyotr Stepanovitch went out without coming to see her, as he had promised, Varvara Petrovna, who had been worn out by anxiety during these days, could not control herself, and ventured to visit her son herself, though it was not her regular time.

She was still haunted by the idea that he would tell her something conclusive.

She knocked at the door gently as before, and again receiving no answer, she opened the door.

Seeing that Nikolay Vsyevolodovitch was sitting strangely motionless, she cautiously advanced to the sofa with a throbbing heart.
She seemed struck by the fact that he could fall asleep so quickly and that he could sleep sitting like that, so erect and motionless, so that his breathing even was scarcely perceptible.