The Fight For a Free Poland

On Sept. 9, 1943, a four-engine British Halifax bomber dropped three Polish paratroopers into their occupied homeland.

- Clare Mulley

Agent Zo

One of them was Elżbieta Zawacka, also known as Zo, the sole female member of an elite unit dubbed the Silent Unseen. According to Zo, when the commander of the local resistance group awaiting the drop rushed forward and threw his arms around her, he abruptly leapt back and exclaimed, "A woman!" "No," she replied, "just an ordinary soldier."

Zo was anything but ordinary, perhaps the most extraordinary individual among a multitude of larger-than-life figures who routinely took enormous risks to free their country from Hitler's overlords. Her life encapsulated Poland's mostly tragic history in the last century, not only during World War II but also under Soviet domination in the postwar era until the country regained its freedom thanks to the Solidarity movement's victory in 1989. Zo, who died just shy of her 100th birthday in 2009, exemplified every stage of that dizzying journey.

In "Agent Zo," the British historian Clare Mulley skillfully weaves together Zawacka's personal story with the broad sweep of events. Ms. Mulley's previous books include "The Spy Who Loved" (2012), a biography of Christine Granville, the adopted name of a Polish woman who worked for Britain's Special Operations Executive, the unit charged with subversion and sabotage in occupied Europe. The author's fascination with the role of women in wartime intrigue is both infectious and mesmerizing.