In Too Deep (The 39 Clues, #6)

Firefly & Fern Summary

In this sixth installment of The 39 Clues series, siblings Amy and Dan Cahill dive deeper into a thrilling global mystery filled with codes, ciphers, and dangerous secrets. As they uncover hidden family history and race against rival branches of their powerful family, young readers will enjoy the fast-paced adventure, puzzle-solving elements, and the bond between brother and sister working together against the odds.