Morality for Beautiful Girls by Alexander McCall Smith
Mma Ramotswe is engaged to "the excellent" Mr. J.L.B. Matekoni, owner of Tlokweng Road Speedy Motors, but faces a slowdown of business at the The No. 1 Ladies' Detective Agency that threatens its existence. Forced to make difficult choices, Mma Ramotswe moves the business into the office of her fiancé's garage and makes her assistant, Mma Grace Makutsi, its assistant manager. At just this time, Mr. J.L.B. Matekoni has been showing signs of lethargy and neglecting his business.