Bizarre and incomprehensible, it arrested Mrs Verloc's attention.

Then as its character became plain to the ear she stopped short, amazed and concerned.

Striking a match on the box she held in her hand, she turned on and lighted, above the parlour table, one of the two gas-burners, which, being defective, first whistled as if astonished, and then went on purring comfortably like a cat.
Mr Verloc, against his usual practice, had thrown off his overcoat.

It was lying on the sofa.

His hat, which he must also have thrown off, rested overturned under the edge of the sofa.