Notoriously known as "La Chatte" ("The Cat"), Mathilde Carré left behind her life as a teacher to join the French Resistance. But when she was captured by the Germans, what motivated her to betray more than 100 members of the Interallié network, the largest spy network in France? Using previously unpublished material from MI5 files, David Tremain tells a story of intrigue, sex, and double-dealing. Tremain also looks for the truth about Carré, who would change allegiances yet again and face charges of treason after the war.