When Leo walked into the sitting room, he found Mara in the exact same position they had left her: hunched over her computer, working. But he was quite sure that she was not doing her normal company work. What he could glimpse on her computer screen looked like it had more to do with research than anything else, and her work had little or nothing to do with that.

She had begun this new activity only recently and had been keeping at it almost every day. Leo had not asked her what it was about and neither had she volunteered to tell him about it. He was curious, of course,...