The Aweful Reason of the Vicar's Visit

"My head went round and round. Was it really true, as I had suddenly fancied a moment before, that unmarried ladies had some dreadful riotous society of their own from which all others were excluded? I remembered dimly in my classical days (I was a scholar in a small way once, but now, alas rusty), I remembered the mysteries of the Bona Dea and their strange female freemasonry. I remembered the witches' Sabbaths. I was just, in my absurd lightheadedness, trying to remember a line of verse about Diana's nymphs, when Miss Mowbray threw her arm round me from behind. The moment it held me I knew it was not a woman's arm.