The front door. The dream of a fourth seacoast : dreams of a seaway ; Three fish : the story of lake trout, sea lampreys; and alewives ; The world's great fishing hole : the introduction of coho and chinook salmon ; Noxious cargo : the invasion of zebra and quagga mussels -- Back door. Continental undivide : Asian carp and Chicago's backwards river ; Conquering a continent : the mussel infestation of the West ; North America's dead sea : toxic algae and the threat to Toledo's water supply -- The future. Plugging the drain : the never-ending threat to siphon away Great Lakes water ; A shaky balancing act : climate change and the fall and rise of the lakes ; A Great Lake revival : charting a course toward integrity, stability, and balance.