This story started here.
My employer looked around the room, apparently confirming that nobody else was going to interrupt, and then she began.
“I’m going to start with Mary, because that’s how the case started for me, and because she did some research which helped me to figure it all out. And because I made a mistake about her, at the beginning, which I want to explain.
“As you all know, Mary came to our house — Marshall and I — on Sunday night, in the middle of the storm. She wanted me to drop everything and rush over here because she said there were ghosts, and Manfred was trying to ‘lay’ them (I believe that’s the technical term).
“Because of the hour, and the storm, and the ridiculousness of the whole idea, I declined, but I agreed to come here on Monday morning. As you know — Jo and Li — we were waiting in Mary’s car when the road became passable, and you told us that there had been a murder.
“I saw immediately what this sequence of events had accomplished. It had given Mary an alibi for the time of the murder. I thought that she had concocted a complicated scheme to murder Manfred and to use me as her alibi, since she had been with me at the moment when the road became impassible for the night, and she was with me when the island was again accessible in the morning.
“To use me in this way would have been audacious, but that was not what actually happened.
“Mary was taking a journalism course, as I’m sure you know, and when she met Manfred, and learned things about him, she decided to write an article about him, exposing him and his various schemes. I’ve read all of her notes, and some of them were written rather cryptically, but it’s pretty obvious that her first plan was to write the article and expose him in that way. But then she thought of a better plan, one which would have made for a much better story.”
She sighed. “What if Manfred was exposed, not by some unknown journalism student at a small liberal arts college, but by a… an internationally known amateur detective and war correspondent, who happens to be living in this town at the moment? Mary’s visit on Sunday night was not to get me to go to the island right then — it was just to start the process of getting me hooked so that I would be the person who would eventually expose Manfred for the fraud he was. After all, if I had decided to drop everything and charge out into the storm to fight the brave fight for science and rationality that night, I would have found that Manfred wasn’t even on the island, or at least he wasn’t here performing any sort of ‘ceremony’ or anything. But she’d been pretty sure I wouldn’t come, and I didn’t.”