The Treasure Troop: The Hidden Room

In the second book of this thrilling code-busting series, Marly, Sai, and Isla are back on the trail of mystery! After uncovering Mr. Summerling's hidden treehouse, they stumble upon a new set of clues that lead them straight into the heart of their enigmatic neighbor's life—his very own house. To their surprise, the house Marly has lived next to for years is filled with hidden rooms and secret staircases. Armed with just a few scraps of paper and with Mr. Summerling's angry son hot on their heels, the Treasure Troop must race to find the answers they seek. Can they solve the puzzles before time runs out?