The case of the hat burglar

"Someone's been stealing from the Lost and Found. But the strangest part of this mystery is what they've been stealing. Not mittens or books or water bottles--only hats! Just when Jigsaw comes up with a plan to catch this Hat Burglar in the act, the mystery thief strikes again, right under his nose! Will this be the first cast Jigsaw and Mia can't solve?"--Dust jacket.