An unlikely series of books about a ladies' detective agency in Africa became a big thing in the publishing world. Their author, and Scottish law professor, Alexander McCall Smith returns to Botswana to rediscover the people and places that inspired him to write these gentle and compelling books. Whilst seeking the real-life counterparts of his detective heroine Mma Ramotswe and Botswana's finest mechanic Mr JLB Matekoni, Muriel Gray teases out the secret of McCall Smith's success - morality.