The Mattigan kids don't believe in things that go bump in the night. After all, their dad is famous for proving such things are impossible. But, when their long-lost Grandpa Joe shows up with his Mysterious Monsters journal, begging for help, the siblings find themselves drawn into a search for Bigfoot. Along the way, they'll have to deal with meddling babysitters, suspicious psychics, a YouTube disaster, and their furious father. To solve this mystery, Maddie, Max, and Theo must rethink what's possible—and make lots of peanut butter and banana sandwiches.

With Bigfoot safely stashed in their basement, Maddie, Max, and Theo Mattigan are off to Las Vegas with their dad. His plan is to prove there are no aliens on the loose there. But now that his kids know that Mysterious Monsters are real, they’re making plans of their own. They’ll need clever disguises, well-hidden walkie-talkies – and more than a few broken eggs – to find out, once and for all, what’s hidden in the notorious Area 51.

Maddie, Max, and Theo have come to the most haunted neighborhood in the most haunted city in America—and they're staying in the spooky Vampire House. While their father searches for evidence to prove its blood-sucker is fake, they set out on a search of their own through a city of the dead to a crumbling Voodoo shack. The Mattigan kids are on the case—but sometimes even the cleverest plan can be a recipe for disaster. Get ready to sink your teeth into their next adventure.

The Mattigan kids convince their dad to go on a mission to find a werewolf, and they are determined to help the monsters hiding in their basement uncover the truth about their pasts. Aligned to Common Core Standards and correlated to state standards. Chapter Books is an imprint of Spotlight, a division of ABDO.

The Mattigan kids have solved the mystery of their monsters' history and their own, but then they learn there's an evil and mysterious creature coming for them. Aligned to Common Core Standards and correlated to state standards. Chapter Books is an imprint of Spotlight, a division of ABDO.