Mallalieu went to Northrop's house to play cards at ten o'clock.

It might be well to find out, quietly, what Mallalieu was doing with himself up to ten o'clock.

But the main thing was--what was Cotherstone doing during that hour of absence?
And--had Cotherstone any reason--of his own, or shared with his partner--for wishing to get rid of Kitely?
Brereton sat thinking all these things over until he had finished his cigar; he then left Bent's house and strolled up into the woods of the Shawl.

He wanted to have a quiet look round the scene of the murder.

He had not been up there since the previous evening; it now occurred to him that it would be well to see how the place looked by daylight.