the time of our leaving him just after midnight, and Miss Comstock’s coming in in the morning.  He admits, however, that twice during that period he fell asleep, but it was only for a few minutes each time; and long years of being constantly alert for possible marauders—­out there in the wilds of Australia—­have tended to make his sleep so light that anything heavier than a cat’s footfall wakes him on the instant.  Yet last night something—­man or spirit—­came and went, and he neither heard nor saw either sound or shape from midnight until morning.  One thing I must tell you, however, which may throw some light upon the movements of the appalling thing.  Whereas Mr. Harmstead not only closed, but locked, both of the two windows in the room, and pinned the thick plushette curtains of them together—­as Miss Comstock and I saw them pinned when we left the room last night—­when those curtains came to be drawn this morning one of the windows was found to be partly open, and there was a smear of something that looked like grease across the sill and the stone coping beyond.”

“Of course, of course!” commented Cleek enigmatically.  “Provided my theory is correct, I should have expected that.  A thing that comes and goes through windows must, at some period, leave some mark of its passage.  Of course that particular window opened upon a balcony or something of that sort, didn’t it?”

“No, it is a perfectly unbroken descent from the window sill to the ground.  But there’s a big tree close by, and the branches of that brush the pane of glass.”

“Ah!  I see!  I see!  All the soap dishes in the house left filled last night and found filled this morning, captain?”

“Good heavens!  I don’t know.  What on earth can soap dishes have to do with it, man?”

“Possibly nothing, probably a great deal—­particularly if there’s found to be a cake of soap in each.  But that we can discover later.  Now one word more.  Was that same minute swelling—­the mark like a gnat’s bite—­on the neck of the boy’s body, too?  And had it been on that of the mother’s as well?”

“I can’t answer either question, Mr. Cleek.  I don’t remember to have heard about it being remarked in the case of Mrs. Comstock’s death; and the murder of little Paul was such a horrible thing and so upset everybody that none of us thought to look.”

“An error of judgment that; however, it is one easily rectified, since the body is not yet interred,” said Cleek.  “Ever read Harvey’s ‘Exercitatio Anatomica de Motu Sanguinis,’ Captain?—­the volume in which William Harvey first gave to the world at large his discovery regarding the circulation of the blood.”

“Good heavens, no!  What would I be doing reading matters of that kind?  I’m not a medico, Mr. Cleek—­I’m a soldier.”