We turned up a side road, and in the failing light I discerned a second car, waiting by the side of the road. It contained two men in plain clothes. Poirot got down and spoke to them, and then we started off in a northerly direction, the other car following close behind.

We drove for some time, our objective being obviously one of the northern suburbs of London. Finally, we drove up to the front door of a tall house, standing a little back from the road in its own grounds.

Norman and I were left with the car. Poirot and one of the detectives went up to the door and rang. A neat parlourmaid opened it. The detective spoke.

“I am a police officer, and I have a warrant to search this house.”

The girl gave a little scream, and a tall, handsome woman of middle-age appeared behind her in the hall.

“Shut the door, Edith. They are burglars, I expect.”