“Who placed it there? and why do you give it to me?” he demanded in surprise.

“Please, sir, it’s directed to you, sir, and I don’t know who put it in my box, sir.  I was on duty, sir, and I ’spose someone must have dropped it on the floor of the box, sir, when I was at the other end of my beat, sir.  It was as dark as this, sir, and I saw nothing and heard nothing.  When I come back, sir, I stepped into the box out of the rain and felt it with my feet.  I struck a light, sir, and found it was for you.”

Sir Frank slipped the package into his pocket and went away after a grim word or so to the sentry, advising him to be more on the alert.  He was puzzled to think who had left the packet in the sentry box, and curious to know what it contained.  As soon as he got to his own room, he cut the string which bound loosely the brown paper.  Then, in the lamplight, there rolled out from the carelessly-tied parcel a glorious sea-green emerald of great size, radiating light like a sun.  A scrap of white paper lay in the brown wrapping.  On it was written, “A wedding gift for Sir Frank Random.”

CHAPTER XXIII

JUST IN TIME

Of all the surprises in connection with the tragedy of the green mummy, this was surely the greatest.  Sidney Bolton had undoubtedly been murdered for the sake of the emeralds, and the assassin had escaped with the spoil, for which he had sold his soul.  Yet here was one of the jewels returned anonymously to Random, who could pass on the same to its rightful owner.  In the midst of his amazement Sir Frank could not help chuckling when he thought how enraged Professor Braddock would be at Don Pedro’s good fortune.  At the eleventh hour, as it were, the Peruvian had got back his own, or at least a portion of his own.

Placing the emerald in his drawer, Random gave orders to his servant that the sentry, when off duty, should be brought before him.  Just as Random finished dressing for mess—­and he dressed very early, so as to devote his entire attention to solving this new problem—­the soldier who had been on guard appeared.  But he could tell nothing more than he had already related.  When doing sentry-go immediately outside the gate of the Fort, the packet had been slipped into the box, while the man was at the far end of his beat.  It was quite dark when this was done, and the soldier confessed that he had not heard a sound, much less had he seen anyone.  The person who had brought the glorious gem had watched his opportunity, and, soft-footed as a cat, had stolen forward in the darkness to drop the precious parcel on the floor of the sentry box.  There the man had found it by the feel of his feet, when he stepped in some time later to escape a shower.  But what time had elapsed from the placing of the parcel to its discovery by the sentry it was impossible to say.  It must, however, as Random calculated, have been within the hour, since, before then, it would not have been dark enough to hide the approach of the person, whether male or female, who carried a king’s ransom in the brown paper parcel.