A one-time director of MI5 (the United Kingdom's primary intelligence organization), she used her vast knowledge to write such crime thrillers as At Risk, Illegal Action, and The Geneva Trap.
After working in Paris as an au pair, she studied English at the University of Edinburgh.
She worked for MI5 from 1967 until 1996.
She grew up in London and Essex, England. She married John Rimington in 1961.
She served as a judge on the Man Booker Prize committee that selected Kiran Desai as a 2006 recipient of the prestigious honor.