I was 3 minutes late for the train. My fiancé gave my window seat to his new intern, draped his blazer over her, and told me to sit in back. I got off before departure—then canceled our wedding.

When I pushed open the mahogany doors, the private room was packed. Vivien sat at the head of the table like a reigning monarch. Donovan looked hollowed out, staring at his water glass. And sitting to his right, wearing a demure white dress, was Juliet.