“Well,” said Brett, “the twist you gave to the reins this morning meant several days added to your pay-sheet.  Would either of you know the man again if you saw him?”

This needed reflection.

“I wouldn’t swear to ’im,” was the driver’s dictum, “but I would swear to any man bein’ like ’im.”

“Same ’ere,” said the conductor.

The barrister understood their meaning, which had not the general application implied by the words.  He obtained the addresses of both men and left them.

His next visit was to an Atlas terminus.  Here he had to wait a full hour before the ’bus arrived that had passed Trafalgar Square on a south journey at 10.45.

The conductor remembered the sudden stoppage of the Road Car vehicle.

“Ran over a man, sir, didn’t it?” he inquired.

“Nearly, not quite.  Now, I want you to fix your thoughts on the passengers who entered your ’bus at that point.  Can you describe them?”

The man smiled.

“It’s rather a large order, sir,” he said.  “I’ve been past there twice since.  If it’s anybody you know particular, and you tell me what he was like, I may be able to help you.”

Brett would have preferred the conductor’s own unaided statement, but seeing no help for it, he gave the man a detailed description of David Hume, plus the beard.

“Has he got black, snaky eyes and high cheek-bones?” the conductor inquired thoughtfully.

The barrister had described a fair man, with brown hair; and the question in no way indicated the colour of the Hume-Frazer eyes.  Yet the odd combination caught his attention.

“Yes,” he said, “that may be the man.”

“Well, sir, I didn’t pick him up there, but I dropped him there at nine o’clock.  I picked him up at the Elephant, and noticed him particular because he didn’t pay the fare for the whole journey, but took penn’orths.”

“I am greatly obliged to you.  Would you know him again?”

“Among a thousand!  He had a funny look, and never spoke.  Just shoved a penny out whenever I came on top.  Twice I had to refuse it.”

“Was he a foreigner?”

“Not to my idea.  He looked like a Scotchman.  Don’t you know him, sir?”

“Not yet.  I hope to make his acquaintance.  Can you remember the ’bus which was in front of you at Whitehall at 10.45?”

“Yes; I can tell you that.  It was a Monster, Pimlico.  The conductor is a friend of mine, named Tomkins.  That is the only time I have seen him to-day.”

At the Monster, Pimlico, after another delay, Tomkins was produced.  Again Brett described David Hume, adorned now with “black, snaky eyes and high cheek-bones.”

“Of course,” said Tomkins.  “I’ve spotted ’im.  ’E came aboard wiv a run just arter a hoss fell in front of the statoo.  Gimme a penny, ‘e did, an’ jumped orf at the ’Orse Guards without a ticket afore we ’ad gone a ’undred yards.  I thort ’e was frightened or dotty, I did.  Know ’im agin?  Ra—­ther.  Eyes like gimlets, ’e ’ad.”