Wolf To The Slaughter by Ruth Rendell
Anita Margolis has vanished. There was no body, no crime - nothing more concrete than an anonymous letter and the intriguing name of Smith. According to headquarters, it wasn't to be considered a murder enquiry at all. Inspector Burden had no trouble in seeing a pattern in the Margolis case. Not only had Anita been wealthy and flighty, she had been thoroughly immoral as well. Decent women had clean, tidy homes, and were either married or had jobs, or both. They didn't live with eccentric artist brothers, or bring lovers home in the afternoon. They also knew enough to keep their money in the bank, not in their handbags. Burden could see exactly what had happened to Anita Margolis. Chief Inspector Wexford, however, had other ideas-