"A bare-footed man or woman came in and killed Mrs.Rider; a second person made the round of the house, trying to get in through one of the windows----" "Whether it was one person or two I cannot tell," replied Ling Chu.
Tarling made a further inspection of the little wing.

It was, as Ling Chu had said and as he had explained to the Chinaman, cut off from the rest of the house, and had evidently been arranged to give Mr.Milburgh the necessary privacy upon his visits to Hertford.

The wing consisted of three rooms; a bedroom, leading from the sitting-room, evidently used by Mrs.Rider, for her clothes were hanging in the wardrobe; the sitting-room in which the murder was committed, and the spare room through which he had passed with Odette to the gallery over the hall.
It was through the door in this room that admission was secured to the house.
"There's nothing to be done but to leave the local police in charge and get back to London," said Tarling when the inspection was concluded.
"And arrest Milburgh," suggested Whiteside.

"Do you accept Ling Chu's theory ?" Tarling shook his head.
"I am loath to reject it," he said, "because he is the most amazingly clever tracker.

He can trace footmarks which are absolutely invisible to the eye, and he has a bushman's instinct which in the old days in China led to some extraordinary results." They returned to town by car, Ling Chu riding beside the chauffeur, smoking an interminable chain of cigarettes.