“I will,” he said slowly, looking hard into my eyes, and feeling my pulse half unconsciously with his finger as he spoke.  “Una darling, you must make up your mind now for a terrible shock.  I won’t tell you in words, for you’d never believe it.  I’ll show you who it was that fired the shot at Mr. Callingham.”

He moved over to the other side of the room, and unlocking drawer after drawer, took a bundle of photographs from the inmost secret cabinet of a desk in the corner.

“There, Una,” he said, selecting one of them and holding it up before my eyes.  “Prepare yourself, darling.  That’s the person who pulled the trigger that night in the library!”

I looked at it and fell back with a deadly shriek of horror.  It was an instantaneous photograph.  It represented a scene just before the one the Inspector gave me.  And there, in its midst, I saw myself as a girl, with a pistol in my hand.  The muzzle flashed and smoked.  I knew the whole truth.  It was I myself who held the pistol and fired at my father!

CHAPTER XIX.

THE REAL MURDERER

For some seconds I sat there, leaning back in my chair and gazing close at that incredible, that accusing document.  I knew it couldn’t lie:  I knew it must be the very handiwork of unerring Nature.  Then slowly a recollection began to grow up in my mind.  I knew of my own memory it was really true.  I remembered it so, now, as in a glass, darkly.  I remembered having stood, with the pistol in my hand, pointing it straight at the breast of the man with the long white beard whom they called my father.  A new mental picture rose up before me like a vision.  I remembered it all as something that once really occurred to me.

Yet I remembered it, as I had long remembered the next scene in the series, merely as so much isolated and unrelated fact, without connection of any sort to link it to the events that preceded or followed it.  It was I who shot my father!  I realised that now with a horrid gulp.  But what on earth did I ever shoot him for?

And I had hunted down Jack for the crime I had committed myself!  I had threatened to give him up for my own dreadful parricide!

After a minute, I rose, and staggered feebly to the door.  I saw the path of duty clear as daylight before me.

“Where are you going?” Jack faltered out, watching me close with anxious eyes, lest I should stumble or faint.

And I answered aloud, in a hollow voice: 

“To the police-station, of course,—­to give myself into custody for the murder of my father.”

When I thought it was Jack, though I loved him better than I loved my own life, I would have given him up to justice as a sacred duty.  Now I knew it was myself, how could I possibly do otherwise?  How could I love my own life better than I loved dear Jack’s, who had given up everything to save me and protect me?