explained to the latter:

"Flack was on duty on the night of the murder but heard no shots.
Probably he was a mile or so away. But in a way he discovered the
crime. Didn't you, Flack? When we rang up Seldon he came up here and
brought Flack with him. He'll be only too glad to tell you anything you
want to know."

Rolfe took an official notebook from a breast pocket and proceeded to
question the police-constable. The inspector made his way upstairs to the
room in which the crime had been committed, for it was his system to seek
inspiration in the scene of a crime.

Tanton Gardens, a short private street terminating in a cul-de-sac, was
in a remote part of Hampstead. The daylight appearance of the street
betokened wealth and exclusiveness. The roadway which ran between its
broad white-gravelled footwalks was smoothly asphalted for motor tyres;
the avenues of great chestnut trees which flanked the footpaths served
the dual purpose of affording shade in summer and screening the houses
of Tanton Gardens from view. But after nightfall Tanton Gardens was a
lonely and gloomy place, lighted only by one lamp, which stood in the
high road more to mark the entrance to the street than as a guide to
traffic along it, for its rays barely penetrated beyond the first pair
of chestnut trees.

The houses in Tanton Gardens were in keeping with the street: they
indicated wealth and comfort. They were of solid exterior, of a size that
suggested a fine roominess, and each house stood in its own grounds.
Riversbrook was the last house at the blind end of the street, and its
east windows looked out on a wood which sloped down to a valley, the