It was a Friday night a few months ago. Rob was standing on my doorstep, ashen and trembling. He still couldn't speak even as he sipped at a mug of tea after my flatmate and I had ushered him into our front room. We could not guess what had happened, but a feeling of dread was fast forming in our minds; we could only assume that something terrible must have happened to Rob's fiancee, Karen. Gradually, his powers of speech returned and the story emerged. Something had happened, but that something was terrible to Rob himself, not Karen.
Now, you have to understand that Rob and Karen were the most balanced, wholesome couple I knew. They had recently moved out of their flat while it was being redecorated, each returning to their respective family homes for a couple of weeks. That Friday, she had left her keys at his place by accident. He was passing by her parents' place later that night, so he stopped off and rang the doorbell.[...]