His superior turning his chair a little, and crossing his thin legs, leaned sideways on his elbow, with one hand shading his eyes.

His listening attitude had a sort of angular and sorrowful grace.

Gleams as of highly burnished silver played on the sides of his ebony black head when he inclined it slowly at the end.
Chief Inspector Heat waited with the appearance of turning over in his mind all he had just said, but, as a matter of fact, considering the advisability of saying something more.

The Assistant Commissioner cut his hesitation short.
"You believe there were two men ?" he asked, without uncovering his eyes.
The Chief Inspector thought it more than probable.

In his opinion, the two men had parted from each other within a hundred yards from the Observatory walls.