“I think I understand how it came here.  Bedney, go around and open the library door leading into this room, and loop back the curtain for a moment.”

“No, sir, Mars Lennox.  Forty railroad ingines couldn’t pull me in there alive.  I wouldn’t dar tamper with ole Marster’s ghost; not for all the money in the bank.  Go yourself; I doesn’t budge on no sech bizness as prying and spying amongst the sperrits.  It would fling me into a fit.”

“You miserable coward.  Is the house open?  Where is the key of this room?”

“Hanging on the horseshoe under my chimbly board.  I’ll fetch it and unlock the front door, so you kin git in, and hold your inquess inside.”

“Will you go, Churchill, or shall I?”

“What is your idea?”

“To ascertain whether the images are on the glass, as I believe, and if they can be seen without the background.  Stand just here—­and watch.  When I pull back the curtain, tell me the effect.”

Some moments later, the red folds shook, swayed aside, the curtain was pushed out of sight on its brass rod.  The interior of the apartment came into view, the articles of furniture, the face and figure of Mr. Dunbar.

“Is it still there; do you see it?” shouted the latter.

“No.  It vanished with the curtain.  Drop it back.  There!  I see it.  Now loop it.  Gone again.  Must be on the curtain,” shouted the Solicitor, peering through the glass at his colleague.

Mr. Dunbar turned a key on the inside, pushed back a bolt, and threw open the door, which swung outward on the veranda.  Then he carefully let fall the plush curtain once more.

“Do you see it?”

“No.  A blank show.  I can’t see into the trick.  Dunbar, change places with me and satisfy yourself.”

The solicitor went inside, and Mr. Dunbar watched from the veranda a repetition of the experiment.

“That will do, Churchill.  It is all plain enough now, but you cease to wonder at Bedney’s superstitious solution.  You understand it perfectly, don’t you?”

“No, I’ll be hanged if I do!  It is the queerest thing I ever saw.”

“Do you recollect that there was a violent thunder-storm the night of the murder?”

“Since you mention it, I certainly recall it.  Go on.”

“All the witnesses testified that next morning this door was closed as usual, but the outside blinds were open, and the red curtain was looped back.”

“Yes, I remember all that.”

“The images are printed on the glass, and were photographed by a flash of lightning.”

“I never heard of such a freak.  Don’t believe it.”