There is the house.

The house of Kozel, the cabinet-maker...

a German, well-to-do.
Lead the way!" They went in from the yard and up to the fourth storey.

The staircase got darker and darker as they went up.

It was nearly eleven o'clock and although in summer in Petersburg there is no real night, yet it was quite dark at the top of the stairs.
A grimy little door at the very top of the stairs stood ajar.