Thunder and Mercy

★ “Set in 1979, the novel captures the freewheeling feel of a Philadelphia summer while weaving in high-stakes Revolutionary War espionage. Thunder is prickly but compelling, determined to prove herself apart from her science-obsessed parents by solving a centuries-old puzzle. Charlie, an earnest eight-year-old with meteorological aspirations and a permanent tie, and his sweet but struggling sister Heather, round out this trio of latchkey sleuths who will inspire readers to form puzzle-solving crews of their own. Barr moves confidently between eras, blending historical fiction with brisk, thrillerlike momentum. The result is an immersive adventure filled with coded messages, spy lore, and the ache of growing up with largely absent parents… A must-purchase for middle grade collections. A lively, genre-blending mystery that will appeal to readers who enjoy historical intrigue, clever puzzles, and a strong-willed heroine.”—School Library Journal, starred review

“An adventure in the vein of Varian Johnson’s The Parker Inheritance and Ruta Sepetys and Steve Sheinkin’s The Bletchley Riddle, this novel has strong secondary characters and a well-established setting… Fun and engaging historical intrigue.”—Kirkus Reviews

“This novel is that killer combination of a dazzling plot with characters who are rich and real and unforgettable.”—Lynda Mullaly Hunt, New York Times best-selling author of Fish in a Tree

“Barr expertly manages both the historical puzzle developed in Mercy’s journal and a modern mystery concerning a local prowler. Readers will cheer for Thunder, a curious and determined adolescent, who after years of loneliness struggles to open herself to the possibility of friendship and connection to an aunt who is genuinely interested in her, and to neighbor siblings Charlie and Heather, who are eager to help her. This lively double historical mystery will captivate readers who enjoyed mysteries like Chasing Vermeer or Under the Egg.”—Booklist

“Barr’s Thunder and Mercy brilliantly draws young readers into the past through a clever and relatable main character whose voice feels fresh and alive. What makes it stand out is the way it balances that energy with meticulous attention to historical detail—small, surprising touches that deepen the story and bring its world vividly to life. It’s both engaging and richly grounded, a combination that will spark curiosity and open new doors to history for young audiences.”—Justina Barrett, chief learning and engagement officer, Historical Society of Pennsylvania, and former site manager for Mount Pleasant