With their father jailed for sinking a river boat, Noah Underwood and his younger sister, Abbey, must gather evidence that the owner of this floating casino is emptying his bilge tanks into the protected waters around their Florida Keys home.

On a beautiful June day in 1965, a dozen girls-classmates at a picturesque Blue Ridge women's college-launched their homemade raft (inspired by Huck Finn's) on a trip down the Mississippi. It's Girls A-Go-Go Down the Mississippi read the headline in the Paducah, Kentucky, paper. Thirty-five years later, four of those "girls" reunite to cruise the river again. This time it's on the luxury steamboat, The Belle of Natchez, and there's no publicity....

In 1806, the exploits of Jacky Faber continue as she heads west to avoid capture by the British and discovers adventure aboard a keelboat on the mighty Mississippi River.