It had been carelessly spoken and Bertha did not dream that anyone had taken notice of her words, or in fact heard them, save her little sister; and Erica, fired by impulse, resolved in that way to avenge the wrongs done to Peggy and her confreres by the tyrannous head prefect, who was so mean and horrid to them.
It never occurred to Erica that the laboratory door might be carefully locked to ensure against any tampering with the unfinished experiments. A weight? A little piece of stone would do. Putty? A bit of plasticine out of one of the tins in her classroom, which was quite near the laboratory! The school-rooms would be deserted now; no one would see her. What could be simpler? And if Duane didn't get her experiment correct, it would serve her right. Oh yes, she deserved it all!
Had Erica paused to think, it would never have been done. But the blind impulse aroused by her passionate adoration of Peggy, drove her straight into the school and up the stairs towards the laboratory.
It was the most extraordinary coincidence that she should be following close on the heels of Kitty, intent on Miss Vacher's errand, though Erica was just too far behind to see her; and also a coincidence that Erica, slipping in noiselessly in her drill shoes (it had been drill last lesson that morning), should neither be seen nor heard by Kitty, who at that moment was at the other end of the room beyond the high-backed benches, pausing in the act of hunting for a clean pipette in order to gaze out of the window to see the reason for the loud noise of a motor engine misfiring on the country road outside. Neither knew of the other's presence. Erica had done her work in a few seconds and was gone before Kitty recrossed the room with the pipette, and left, locking the door again behind her.
But the point of the whole affair lay in the fact that Erica, who had not stopped to think, and was in such a state of agitation as hardly to know what she was doing, made a mistake over the balances and weighted Salome's instead of Duane's. She had heard Eileen describe herself as in the middle of the first bench near the door, with Salome on her right and Duane on her left, but she did not stop to consider which would be Eileen's right and which her left; there was the end of the bench conveniently just inside the door, and in her agitation it did not dawn upon her that Duane might be at the other end. "Which shows," Duane put in somewhat quaintly, "that she was not cut out for a conspirator, at any rate."
Then had come the inquiry in the hall and with it so complete a realization of the enormity of the thing which she had done, that the highly-strung, sensitive child, with visions of awful punishments floating before her eyes, could no more come forward and confess her guilt in front of them all than she could have taken wings and flown.
"Up to then," went on Duane, "I knew no more about the affair than any of you. All I knew was that the keys had never left my possession during the dinner interval save once. I had not done it myself; I could only think Kitty was the culprit. I am afraid," looking across at Kitty, "I did you an injustice there."
"And I," responded Kitty with a smile, "knew I hadn't done it, and I could only think you had. We were both mistaken. Of course, what put us all on the wrong track was the fact that it was Salome's balances that had been meddled with. She's so popular with all the girls. We could only put it down to motives of house jealousy."
"Well, up till the evening, as I said, I was as much in the dark as anyone," continued Duane, and went on to narrate how she had received a visit from Bertha and a white, trembling Erica, who had confessed to her older sister what she had done, knowing that Bertha would somehow help her. Bertha, startled and horrified, had sternly enjoined the younger child that on no account must she breathe a word of it to anyone else until she, Bertha, gave her permission. Bertha meant that it should never have been found out, if she could help it, no matter what happened.
But she had to do something to calm the frightened, conscience-stricken child. They could tell Duane, she said, and ask her advice. She was the one Erica had meant to injure.