The Spy with the Red Balloon

Siblings Ilse and Wolf hide a deep secret in their blood: with it, they can work magic. And the government just found out.

Blackmailed into service during World War II, Ilse lends her magic to America’s newest weapon, the atom bomb, while Wolf goes behind enemy lines to sabotage Germany’s nuclear program. It’s a dangerous mission, but if Hitler were to create the bomb first, the results would be catastrophic.

When Wolf’s plane is shot down, his entire mission is thrown into jeopardy. Wolf needs Ilse’s help to develop the magic that will keep him alive, but with a spy afoot in Ilse’s laboratory, the letters she sends to Wolf begin to look treasonous. Can Ilse prove her loyalty—and find a way to help her brother—before their time runs out?

  • 368 Pages
  • 5.5" x 8.25"
  • 9780807529386
  • October 2019

Buy from Albert Whitman

  • 9780807529362
  • October 2018

Other Places to Buy


  • Ilse is a complicated, fascinating protagonist, and her scientific mind will draw in teens… it has broad appeal for alt-history and urban fantasy readers.

    - Booklist

  • An entertaining and thoughtful sequel

    - Foreword Review

  • A fast-moving read sure to delight those who enjoy historical fiction.

    - School Library Journal