Mattie loves her aunt and the shop, even if she's still dealing with a life without her mom. But not everybody is a fan of Owl's Outstanding Donuts.
When an owl taps on Mattie's window one night, Mattie looks out to see suspicious activity not far from the shop. A shady duo is dumping gloop near the highway. And soon people want to blame Aunt Molly! With help from her friends, Mattie sets out to find the real gloopers. Along the way, she'll face fears that have followed her since her mother's passing--and get to know Alfred, a stuffy, donut-loving owl who's also on the case.

"Readers of all ages will be cheering--and hooting!--for Mattie and her friends as they track down the culprits in this brilliant, high-stakes mystery with heart. Owl's Outstanding Donuts is, well, simply outstanding!"--Kristen Kittscher, author of The Wig in the Window