Rebecca Zamolo has managed to foil the Game Master's plans before, but this time the Game Master has snake-napped Nacho, her good friend Miguel's pet. No way is Becca going to let the Game Master get away with this dastardly plan. But when the clues lead Becca and her new friends in the direction of the one house in their entire neighborhood that none of them ever want to go near, they know they have no choice but to screw up their courage and dare to investigate, if they want to rescue Nacho.But the problem is that getting into the superspooky house is way easier than getting out. The Game Master is up to their old tricks, and Becca, Matt, Kylie, Frankie, and Miguel are going to have to face their fears and use all their smarts and strengths to solve the puzzles and games and save the day.Mansion Mystery is another action-packed adventure from New York Times bestselling authors and super-sleuthing team Rebecca and Matt Zamolo, stars of the hugely popular Game Master Network.