There is always more history to tell. Even in a subject as exhaustively covered as World War II, there is always more to tell.

Still, it's surprising when the unknown heroes include someone the Gestapo considered "the most dangerous of all Allied spies." Or, maybe not so surprising: Her name was Virginia Hall.

In "A Woman of No Importance," London journalist Sonia Purnell has written a riveting account of Hall's work as a ferociously courageous American spy, yet whose mother never quite forgave her for failing to marry a rich man.

Hall's flouting of womanly expectations was a path to her success, but also provoked a continuing challenge to her authority.

When a British intelligence division was struggling to find people "able to pursue a noble cause with piratical daring," no one considered women for the work, much less a secretary such as Hall.

Yet when she impressed an operative with her organizational skills and, more to the point, her utter fearlessness, she was sent to France as an American journalist, where she secretly coordinated the work of local Resistance leaders.

Perhaps her greatest cover was that she also was an amputee who'd lost most of her left leg in a hunting accident. With dry humor, she'd named her wooden leg Cuthbert.

Purnell's research is impressive, with extensive footnotes and a lengthy bibliography. And good thing, because the work of spies such as Virginia — Purnell calls her Virginia — is mind-boggling.

She recruited peasants and prostitutes as spies, masterminded prison escapes, organized parachute drops of weapons such as fake horse dung that exploded if driven over.

Most daring were her radio transmissions to London, keeping her on the move from village to village, attic to attic, to elude detection. The Germans were wild to find her.

Capture meant certain torture with diabolical methods for women, and eventual execution.

Yet her most vexing concerns were dealing with fellow spies who were incompetent, or who resented taking orders from a woman, or were dismissive of her accomplishments.

Purnell writes with compelling energy and fine detail. Passages about German torturer Klaus Barbie are emotionally wrenching. She avoids romantic flights about wartime valor. She quietly conveys Resistance fighters' frank acceptance that fighting for one's country is not only worth their sweat, but their lives.

Peace led, perhaps predictably, to Virginia's downward spiral. She was a war hero, but people were moving on.

She became one of the first women to join what soon was the CIA, working on Cold War activities. But there were no more attic hideaways, midnight airdrops, clandestine meetings in bars with crucial back doors. Only desks in D.C., and younger men who wondered why this aging woman had such an attitude about being taken seriously.

Virginia's work will be remembered. This book has been optioned for a movie starring Daisy Ridley, the newest "Star Wars" heroine. But Purnell reminds how much history there is to tell.

Kim Ode is a former features writer for the Star Tribune.

A Woman of No Importance
By: Sonia Purnell.
Publisher: Viking, 352 pages, $28.