The Lunch Club face off against a scary, hairy foe in this Halloween mystery! Tia and Leo narrowly escaped the clutches of the awful alien Zaralgax, only to face the terror of the . . . Pleasantwood Elementary Science Fair? Thanks to Mr. Peabody, their exhibit is about stamps -- a subject so terrifyingly boring they might not survive until the next Lunch Club meet-up. Against all odds, they do, just in time to plan their costumes for the big Halloween party.