Jetson was on his way home from his office in the Finchley Road. There
had been a mist hanging about all day, and with nightfall it had
settled down into a whitish fog. Soon after leaving the Finchley Road,
Jetson noticed in front of him a man wearing a long, yellow mackintosh,
and some sort of soft felt hat. He gave Jetson the idea of being a
sailor; it may have been merely the stiff, serviceable mackintosh. At
the corner of Laleham Gardens the man turned, and glanced up at the
name upon the lamp-post, so that Jetson had a full view of him.
Evidently it was the street for which he was looking. Jetson, somewhat
curious, the Hepworths' house being still the only one occupied, paused
at the corner, and watched. The Hepworths' house was, of course, the
only one in the road that showed any light. The man, when he came to
the gate, struck a match for the purpose of reading the number.
Satisfied it was the house he wanted, he pushed open the gate and went
up the path.

But, instead of using the bell or knocker, Jetson was surprised to hear
him give three raps on the door with his stick. There was no answer,
and Jetson, whose interest was now thoroughly aroused, crossed to the
other corner, from where he could command a better view. Twice the man
repeated his three raps on the door, each time a little louder, and the
third time the door was opened. Jetson could not tell by whom, for
whoever it was kept behind it.

He could just see one wall of the passage, with a pair of old naval
cutlasses crossed above the picture of a three-masted schooner that he
knew hung there. The door was opened just sufficient, and the man
slipped in, and the door was closed behind him. Jetson had turned to
continue his way, when the fancy seized him to give one glance back.
The house was in complete darkness, though a moment before Jetson was
positive there had been a light in the ground floor window.

It all sounded very important afterwards, but at the time there was
nothing to suggest to Jetson anything very much out of the common.
Because for six months no friend or relation had called to see them,
that was no reason why one never should. In the fog, a stranger may
have thought it simpler to knock at the door with his stick than to
fumble in search of a bell. The Hepworths lived chiefly in the room at
the back. The light in the drawing-room may have been switched off for
economy's sake. Jetson recounted the incident on reaching