Nobody took much notice when the handbag slashing began in London. A few women found small nicks in their handbags, others huge gashes. John Coffin, however, has the feeling that the cases are going to lead to something different and, when a similar case in Scotland ends up with a murder, the chase is on. Gwendoline Butler is one of the most universally praised of English crime writers, under her own name and that of Jennie Melville.