“Thank you, Wilkins,” said Thorndyke. “And now what are we to give you for your trouble in coming here?”

“I’ll leave the fare to you, sir. You know what the information’s worth; but I should think ’arf a thick-un wouldn’t hurt you.”

Thorndyke laid on the table a couple of sovereigns, at the sight of which the cabman’s eyes glistened.

“We have your address, Wilkins,” said he. “If we want you as a witness we shall let you know, and if not, there will be another two pounds for you at the end of a fortnight, provided you have not let this little interview leak out.”

Wilkins gathered up the spoils gleefully. “You can trust me, sir,” said he, “for to keep my mouth shut. I knows which side my bread’s buttered. Good night, gentlemen all.”

With this comprehensive salute he moved towards the door and let himself out.