"It's wet, it's loud and it's enormous! It's Niagara Falls! Grant and Christina can't wait to go on another trip with their grandparents Mimi and Papa. Mimi writes mysteries and mystery never fails to follow the kids wherever they go including this wild and wonderful place! Along with new friends Allison and David, Grant and Christina spy b-b-b-bouncing barrels, discover a secret room, visit a famous fort, ride a Ferris wheel (Wheeee!!!), learn about locks and solve a soggy mystery! Loooook ouuuuuut! There's another barrel coming down the falls! But what's in it? Hey-don't forget your raincoat! You're going to get wet!!!''--P. [4] of cover.