Tiny Luttrell by E.W. Hornung

But the girl herself chose to think otherwise. That was her perversity. She could now see excuses for her own ill-treatment in the past, but none for the revenge she had just taken on the man who had treated her badly. A revenge it had certainly been, plotted systematically, and carried out from first to last in sufficiently cold blood. But already she was ashamed of it. So sincerely ashamed was Christina, now that she had completed her retaliation and secured her triumph, that she very much exaggerated the evil she had done, and could imagine no baser behavior than her own. She had, indeed, felt the baseness of it while yet there was time to draw back, but the memory of her own humiliation had been her goad whenever she hesitated; and then the way had been made irresistibly easy for her. But this was no comfort to her now. Neither was that goad any excuse to her self-accusing mind; for she could feel it no longer, which made her wonder how she had ever felt it at all.

Her judgment was obscured by the magnitude of her meanness in her own eyes. The revulsion of feeling was as complete as it was startling and distressing to herself.