“You are no longer connected with headquarters, I presume.  But—­ can you get men?”

“If need be.”

“You will need them!” Just then Watson noticed the uniform of General Hume.  “Jerome, can you give this officer a bodyguard?”

It was both unusual and lightning-sudden.  Nevertheless, there was something in Watson’s manner that called for no challenge; something that would have brooked no refusal.  And the general, although a sceptic, was acting solely from force of habit when he objected: 

“It seems to me, Watson, that you—­”

Those who were present are not likely to forget it.  Some men are born, some rise, to the occasion; but Watson was both.  He was clear-cut, dominant, inexorable.  He levelled his pencil at the general.

“It seems to you!  General, let me ask you:  If your country’s safety were at stake, would you hesitate to throw reinforcements into the breach?”

“Hardly.”

“All right.  It’s settled.  Take care of your red tape afterwards.”

He wheeled to the detective.  “Jerome, this is a sketch of the compartments of Dr. Holcomb’s safe.  Not the large one in his house, but the small one in his laboratory.  Go straight to Dwight Way.  Give this note,” indicating another paper, “to Bertha Holcomb.  Tell her that her father is safe, and that I am out of the Blind Spot.  Tell her you have come to open the laboratory safe.  I’ve written down the combination.  If it doesn’t work use explosives; there’s nothing inside which force can harm.  In the compartment marked ‘X’ you will find a small particle about the size of a pea, wrapped in tin-foil, and locked in a small metal box.  You will have to break the box.  As for the contents, once you see the stone you can’t mistake it; it will weigh about six pounds.  Get it, and guard it with your life!”

“All right.”

Jerome put Watson’s instructions in his wallet, at the same time glancing about the room.

“Where is Fenton?” he asked.

It was Watson who answered.  He gave us the first news that had ever come from the Blind Spot.  He spoke with firm deliberation, as though in full realisation of the sensation: 

“Hobart Fenton has gone through the Blind Spot.  Just now he is right here in this room.”

Sir Henry jumped.

“In this room!  Is that what you said, Watson?”

The other ignored him.

“Jerome, you haven’t a minute to lose!  You and the general; bring that stone back to this house at any cost!  Hurry!”

In another moment Jerome and Hume were gone.  And few people, that day, suspected the purport of that body of silent men who crossed over the Bay of San Francisco.  They were grim, and trusted, and under secret orders.  They had a mission, did they but know it, as important as any in history.  But they knew only that they were to guard Jerome and the general at all hazards.  One peculiarly heavy stone, “the size of a pea”!  How are we ever to calculate its value?