“Not quite so loud, if you please, sir,” said the sergeant.  “I think there is somebody coming up Crown Office Row.”

The ball had, in fact, opened.  As we peered cautiously out of the open window, keeping well back in the darkened room, a stealthy figure crept out of the shadow, crossed the road, and stole noiselessly into the entry of Thorndyke’s chambers.  It was quickly followed by a second figure, and then by a third, in which I recognized our elusive client.

“Now listen for the signal,” said Thorndyke.  “They won’t waste time.  Confound that clock!”

The soft-voiced bell of the Inner Temple clock, mingling with the harsher tones of St. Dunstan’s and the Law Courts, slowly told out the hour of midnight; and as the last reverberations were dying away, some metallic object, apparently a coin, dropped with a sharp clink on to the pavement under our window.

At the sound the watchers simultaneously sprang to their feet.

“You two go first,” said the sergeant, addressing the uniformed men, who thereupon stole noiselessly, in their rubber-soled boots, down the stone stairs and along the pavement.  The rest of us followed, with less attention to silence, and as we ran up to Thorndyke’s chambers, we were aware of quick but stealthy footsteps on the stairs above.

“They’ve been at work, you see,” whispered one of the constables, flashing his lantern on to the iron-bound outer door of our sitting-room, on which the marks of a large jemmy were plainly visible.

The sergeant nodded grimly, and, bidding the constables to remain on the landing, led the way upwards.

As we ascended, faint rustlings continued to be audible from above, and on the second-floor landing we met a man descending briskly, but without hurry, from the third.  It was Mr. Barton, and I could not but admire the composure with which he passed the two detectives.  But suddenly his glance fell on Thorndyke, and his composure vanished.  With a wild stare of incredulous horror, he halted as if petrified; then he broke away and raced furiously down the stairs, and a moment later a muffled shout and the sound of a scuffle told us that he had received a check.  On the next flight we met two more men, who, more hurried and less self-possessed, endeavoured to push past; but the sergeant barred the way.

“Why, bless me!” exclaimed the latter, “it’s Moakey; and isn’t that Tom Harris?”

“It’s all right, sergeant,” said Moakey plaintively, striving to escape from the officer’s grip.  “We’ve come to the wrong house, that’s all.”

The sergeant smiled indulgently.  “I know,” he replied.  “But you’re always coming to the wrong house, Moakey; and now you’re just coming along with me to the right house.”

He slipped his hand inside his captive’s coat, and adroitly fished out a large, folding jemmy; whereupon the discomforted burglar abandoned all further protest.