“Something here!” he said, loudly enough to reach the ears of Bryce and his companions.  “Not so deep down, neither, gentlemen!”

A few vigorous applications of the trowel, a few lumps of earth cast out of the cavity, and the master-mason put in his hand and drew forth a small parcel, which in the light of the lamp held close to it by Mitchington looked to be done up in coarse sacking, secured by great blotches of black sealing wax.  And now it was Harker who nudged Bryce, drawing his attention to the fact that the parcel, handed by the master-mason to Mitchington was at once passed on by Mitchington to the Duke of Saxonsteade, who, it was very plain to see, appeared to be as much delighted as surprised at receiving it.

“Let us go to your office, inspector,” he said.  “We’ll examine the contents there.  Let us all go at once!”

The three figures behind the cypress trees remained immovable and silent until the five searchers had gone away with their lamps and tools and the sound of their retreating footsteps in Friary Lane had died out.  Then Dick Bewery moved and began to slip off, and Bryce reached out a hand and took him by the shoulder.

“I say, Bewery!” he said.  “Going to tell all that?”

Harker got in a word before Dick could answer.

“No matter if he does, doctor,” he remarked quietly.  “Whatever it is, the whole town’ll know of it by tomorrow.  They’ll not keep it back.”

Bryce let Dick go, and the boy immediately darted off in the direction of the close, while the two men went towards Harker’s house.  Neither spoke until they were safe in the old detective’s little parlour, then Harker, turning up his lamp, looked at Bryce and shook his head.

“It’s a good job I’ve retired!” he said, almost sadly.  “I’m getting too old for my trade, doctor.  Once upon a time I should have been fit to kick myself for not having twigged the meaning of this business sooner than I have done!”

“Have you twigged it?” demanded Bryce, almost scornfully.  “You’re a good deal cleverer than I am if you have.  For hang me if I know what it means!”

“I do!” answered Harker.  He opened a drawer in his desk and drew out a scrap-book, filled, as Bryce saw a moment later, with cuttings from newspapers, all duly arranged and indexed.  The old man glanced at the index, turned to a certain page, and put his finger on an entry.  “There you are!” he said.  “And that’s only one—­there are several more.  They’ll tell you in detail what I can tell you in a few words and what I ought to have remembered.  It’s fifteen years since the famous robbery at Saxonsteade which has never been accounted for—­robbery of the Duchess’s diamonds—­one of the cleverest burglaries ever known, doctor.  They were got one night after a grand ball there; no arrest was ever made, they were never traced.  And I’ll lay all I’m worth to a penny-piece that the Duke and those men are gladding their eyes with the sight of them just now!—­in Mitchington’s office—­and that the information that they were where they’ve just been found was given to the Duke by—­Glassdale!”