Starred Review In her first series, Hannigan (The Detective's Assistant, 2015) deposits readers into WWII-era Philadelphia, where they'll encounter the women mathematicians known as the ENIAC Six, female superheroes from early comic books, and a real Nazi spy ring. Twelve-year-old Irish immigrant Josie O'Malley feels the pinch of wartime living, picking up shifts at a diner and caring for her younger siblings while her mother works and her father fights in the Pacific. She desperately wishes the superheroes from her beloved comics would help her troubled city, but little does she suspect that she's about to become one herself. After responding to a newspaper ad calling for puzzlers (she's an ace at math and pattern recognition), Josie is recruited with two other girls rican American Mae and Japanese American Akiko to a secret organization. Incredibly, the girls manifest superpowers just as a supervillain begins terrorizing the city. Prejudice against girls and women and racism directed at Mae and Akiko provide a more serious side to the action-packed plot. Humorous touches emerge as Josie and her friends hone their new powers, and some cheesy one-liners give a wink to vintage comic books do illustrated comics spreads. Readers across genres will be enamored by this blend of history, mystery, and superpowered action. A thorough author's note supplies historical context for the trio's first adventure.

Superheroes, spies, puzzle solvers—or all three?It's World War II, and Zenobia, Black Cat, and the other superheroes vanished from the streets of Philadelphia a couple of years ago. Josie, a white Irish immigrant, is despairing, with a war on and her beloved heroes all missing. At least Josie can do her part for the war effort, since a call has gone out for puzzle-solving and mathematically inclined kids. Just when it looks like Josie won't be able to help—are her excellent ciphering skills going to be ignored just because she's a girl?—a mysterious woman solicits the help of Josie and two other puzzler girls: Akiko, a Japanese-American girl whose family is in an internment camp, and Mae, a black girl whose grandmother is a librarian, both also cipher- and comics-loving superhero fans. And somehow, when the three of them get together, they have powers! Like the heroes of their favorite comics, the girls whoosh through the skies, caped rescuers fighting Nazis. Along the way they meet and rescue the women who are the first computer programmers. Mae and Akiko encounter a smidgen of racism, although far, far milder than accuracy would call for; this is a superhero/puzzling/Nazi-thwarting tale, not historical fiction. With interwoven action sequences told in comics panels, the tale has the exciting pace of a superhero adventure.Puzzles readers can solve are the icing on this cake. (historical note, further resources) (Historical fantasy. 9-11)