They Do It With Mirrors by Agatha Christie

I’m only a bastard, aren’t I? Only a bastard. You went on filling me up with lies. Pretending to be kind to me, and all the time—all the time … you’re not fit to live. I won’t let you live.”
    Again there came a stream of obscene profanity. Somewhere during the scene Miss Marple was conscious of Miss Bellever saying:
    â€œWe must do something,” and leaving the Hall.
    Edgar seemed to pause for breath and then he shouted out,
    â€œYou’re going to die—to die. You’re going to die now. Take that, you devil, and that! ”
    Two sharp cracks rang out—not in the park this time, but definitely behind the locked door.
    Somebody, Miss Marple thought it was Mildred, cried out:
    â€œOh God, what shall we do?”
    There was a thud from inside the room and then a sound, almost more terrible than what had gone before, the sound of slow, heavy sobbing.
    Somebody strode past Miss Marple and started shaking and rattling the door.
    It was Stephen Restarick.
    â€œOpen the door. Open the door,” he shouted.
    Miss Bellever came back into the Hall. In her hand she held an assortment of keys.
    â€œTry some of these,” she said breathlessly.
    At that moment the fused lights came on again. The Hall sprang into life again after its eerie dimness.
    Stephen Restarick began trying the keys.
    They heard the inside key fall out as he did so.
    Inside, that wild desperate sobbing went on.
    Walter Hudd, coming lazily back into the Hall, stopped dead and demanded:
    â€œSay, what’s going on round here?”
    Mildred said tearfully,
    â€œThat awful crazy young man has shot Mr. Serrocold.”
    â€œPlease.” It was Carrie Louise who spoke. She got up and came across to the study door. Very gently she pushed Stephen Restarick aside. “Let me speak to him.”
    She called—very softly—“Edgar … Edgar … let me in, will you? Please, Edgar.”
    They heard the key fitted into the lock. It turned and the door was slowly opened.
    But it was not Edgar who opened it. It was Lewis Serrocold. He was breathing hard as though he had been running, but otherwise he was unmoved.
    â€œIt’s all right, dearest,” he said. “Dearest, it’s quite all right.”
    â€œWe thought you’d been shot,” said Miss Bellever gruffly.
    Lewis Serrocold frowned. He said with a trifle of asperity:
    â€œOf course I haven’t been shot.”
    They could see into the study by now. Edgar Lawson had collapsed by the desk. He was sobbing and gasping. The revolver lay on the floor where it had dropped from his hand.
    â€œBut we heard the shots,” said Mildred.
    â€œOh yes, he fired twice.”
    â€œAnd he missed you?”
    â€œOf course he missed me,” snapped Lewis.
    Miss Marple did not consider that there was any of course about it. The shots must have been fired at fairly close range.
    Lewis Serrocold said irritably:
    â€œWhere’s Maverick? It’s Maverick we need.”
    Miss Bellever said:
    â€œI’ll get him. Shall I ring up the police as well?”
    â€œPolice? Certainly not.”
    â€œOf course, we must ring up the police,” said Mildred. “He’s dangerous.”
    â€œNonsense,” said Lewis Serrocold. “Poor lad. Does he look dangerous?”
    At the moment he did not look dangerous. He looked young and pathetic and rather repulsive.
    His voice had lost its carefully acquired accent.
    â€œI didn’t mean to do it,” he groaned. “I dunno what came over me—talking all that stuff—I must have been mad.”
    Mildred sniffed.
    â€œI really must have been mad. I didn’t mean to. Please, Mr. Serrocold, I really didn’t mean to.”
    Lewis Serrocold patted him on the shoulder.
    â€œThat’s all right, my boy. No damage done.”
    â€œI might have killed you, Mr. Serrocold.”
    Walter Hudd walked across the room and peered at the wall