Twelve-year-old globetrotter Thea Lim-Lambert is spending a rare summer at home in Brooklyn, when she discovers a secret room in the back of her closet. There, among her grandfather Errol's old diaries and peculiar carvings, is a clue Errol left to a massive hidden treasure. But to find it, she'll need the help of two experienced sleuths--lucky for her, two of the best live in her building!

Roya and Amin's mystery podcast has earned them a stellar reputation, but they never could have guessed that their latest case would send them on a wild scavenger hunt in their own building. Clue by clue, they search the building from roof to cellar (thanks to Roya's mom's master key). But just when a solution seems near, they realize an essential piece is missing--locked away where none of them can reach it. And unless Thea finds the courage to stand up to her family the treasure of Ocean Parkway may be lost forever. . .

"A twisty mystery, a heartwarming adventure, and a love letter to New York that is equal parts Nancy Drew and Only Murders in the Building." --James Ponti, New York Times bestselling author of City Spies and The Sherlock Society