The spoilt kill

First published in 1961, this innovative mystery from Kelly (1927--2017) effectively uses time shifts to create suspense. The owner of a Staffordshire pottery company has hired PI Hedley Nicholson to shadow an employee, designer Corinna Wakefield, because he suspects Corinna of stealing new designs on the behalf of a rival firm. After two weeks keeping an eye on Corinna while posing as a consultant, Nicholson joins a tour she's conducting of the pottery factory. In one building, while the people on the tour are distracted, Nicholson notices a shocked expression on Corinna's face after she raises the trapdoor of a vault that holds liquid clay. Inside is a dead body. Nicholson recognizes the person, whose identity remains a tantalizing secret well into the book. A lengthy flashback charts the events leading up to that grim find, and a final section focuses on the murder and industrial spying. Subtle characterizations enhance the well-crafted plot. This is a superior addition to the British Crime Classics series. (Dec.)