Mr. Draycott folded the cheque with thoughtful deliberation and put it carefully away in his pocket-book.

“I don’t know whether you’ve guessed as much, sir,” he said in a queer voice, “but I think that you’ve saved a man’s life to-day.  It’s not the money, it’s the encouragement ... and faith.  If you could see you’d know better than I can say how I feel about it.”

Carrados laughed quietly.  It always amused him to have people explain how much more he would learn if he had eyes.

“Then we’ll go on to Lucas Street and give the manager the shock of his life,” was all he said.  “Come, Mr. Draycott, I have already rung up the car.”

But, as it happened, another instrument had been destined to apply that stimulating experience to the manager.  As they stepped out of the car opposite “The Safe” a taxicab drew up and Mr. Carlyle’s alert and cheery voice hailed them.

“A moment, Max,” he called, turning to settle with his driver, a transaction that he invested with an air of dignified urbanity which almost made up for any small pecuniary disappointment that may have accompanied it.  “This is indeed fortunate.  Let us compare notes for a moment.  I have just received an almost imploring message from the manager to come at once.  I assumed that it was the affair of our colonial friend here, but he went on to mention Professor Holmfast Bulge.  Can it really be possible that he also has made a similar discovery?”

“What did the manager say?” asked Carrados.

“He was practically incoherent, but I really think it must be so.  What have you done?”

“Nothing,” replied Carrados.  He turned his back on “The Safe” and appeared to be regarding the other side of the street.  “There is a tobacconist’s shop directly opposite?”

“There is.”

“What do they sell on the first floor?”

“Possibly they sell ‘Rubbo.’  I hazard the suggestion from the legend ‘Rub in Rubbo for Everything’ which embellishes each window.”

“The windows are frosted?”

“They are, to half-way up, mysterious man.”

Carrados walked back to his motor-car.

“While we are away, Parkinson, go across and buy a tin, bottle, box or packet of ‘Rubbo.’”

“What is ‘Rubbo,’ Max?” chirped Mr. Carlyle with insatiable curiosity.

“So far we do not know.  When Parkinson gets some, Louis, you shall be the one to try it.”

They descended into the basement and were passed in by the grille-keeper, whose manner betrayed a discreet consciousness of something in the air.  It was unnecessary to speculate why.  In the distance, muffled by the armoured passages, an authoritative voice boomed like a sonorous bell heard under water.

“What, however, are the facts?” it was demanding, with the causticity of baffled helplessness.  “I am assured that there is no other key in existence; yet my safe has been unlocked.  I am given to understand that without the password it would be impossible for an unauthorized person to tamper with my property.  My password, deliberately chosen, is ‘anthropophaginian,’ sir.  Is it one that is familiarly on the lips of the criminal classes?  But my safe is empty!  What is the explanation?  Who are the guilty persons?  What is being done?  Where are the police?”