Book excerpt: A classic Agatha Christie short story from the collection The Golden Ball and Other Stories. Jane Cleveland is in desperate need of a job, and when she sees an ad for a woman of her description needed to impersonate a grand duchess, she cannot believe her luck. The royal retainers tell Jane that the job will be dangerous because attempts have been made on the Grand Duchess Pauline’s life, but this only serves to make the job more appealing. Jane’s disguise initially goes according to plan, but when she is kidnapped and drugged, it appears that her new employers are not all that they seem…