Strong Poison by Dorothy L Sayers

Miss Murchison felt a touch of excitement in her well regulated heart, as she rang the bell of Lord Peter's flat. It was not caused by the consideration of his title or his wealth or his bachelorhood, for Miss Murchison had been a business woman all her life, and was accustomed to visiting bachelors of all descriptions without giving a second thought to the matter. But his note had been rather exciting.

Miss Murchison was thirty-eight, and plain. She had worked in the same financier's office for twelve years. They had been good years on the whole, and it was not until the last two that she had even begun to realise that the brilliant financier who juggled with so many spectacular undertakings was juggling for his life under circumstances of increasing difficulty. As the pace grew faster, he added egg after egg to those which were already spinning in the air. There is a limit to the number of eggs which can be spun by human hands. One day an egg slipped and smashed -- then another -- then a whole omelette of eggs. The juggler fled from the stage and escaped abroad, his chief assistant blew out his brains, the audience booed, the curtain came down, and Miss Murchison, at 37, was out of a job.