“Sorry,” he muttered somewhat ungraciously. “You’re right, of course. But——”

“But there’s nothing to add to your story to-night. Take my word for it,” said Snell, with restored good humour. “Which way are you going? Tube? I’m for the tram. What a beastly night! I shan’t be sorry to get indoors.”

“Nor I,” Austin confessed with a shiver.

Almost in silence they walked side by side through the chill drizzle to the station, and there parted, Snell crossing to the tram terminus.

But he was not yet bound for home, as he had allowed and wished Starr to infer. Tireless and relentless as a sleuth-hound, he believed he was already fairly on the track of Lady Rawson’s murderer, but there were certain preliminary points he wished to clear up, and till he succeeded in that there would be no rest for him.

The tram was crowded with returning theatre-goers, most of whom were discussing the grim crime and the reports in the late editions of the evening papers. None guessed how intimately the wiry little man in the drenched Burberry, meekly strap-hanging among them, was concerned with it, and quite a number alighted from the tram when he did, opposite the post office, and lingered in the rain staring at the house of tragedy, now dark and silent as a grave, with a solitary policeman standing guard, and in a subdued, monotonous voice requesting the whispering crowd to “Pass along, please.”

Snell did not even glance at the house or the sentinel, but disappeared into the darkness of the square nearly opposite, three sides of which were occupied by the tall blocks of flats known as “Rivercourt Mansions,” fronted by shrubberies, and with more shrubs and trees in the centre: a pleasant place enough in daylight, but gloomy and mysterious on this miserable wet midnight. Treading as lightly as a cat in his “silent-soled” shoes, Snell walked swiftly to the end of the square, and paused, to be joined immediately by a man in a dark mackintosh, who emerged from the shadow of the shrubs.

“Anything to report, Evans?” Snell asked softly.

“He hasn’t returned yet, sir. Mr. Starr went in and stayed a good few minutes, just after ten-thirty.”

“I know. Did he see you?”