When canine heroes Max, Rocky, and Gizmo encounter a lavish riverboat moored close to shore, they're wary of what they might find on board. But as they're welcomed by a friendly community of dogs, the trio discover that there's more to their new world than they expected. These dogs have seen humans -- who Max, Rocky, and Gizmo thought had disappeared without a trace.The brave companions meet new friends and encounter old enemies in their search for their people, traveling to places they never imagined -- from a high-speed monorail to a zoo filled with exotic animals. Max, Rocky, and Gizmo uncover secrets that promise to change their lives forever as they draw closer to figuring out why the humans left and being reunited with their families. "The Last Dogs: Dark Waters" is the second book in a thrilling series about three friends on a journey to find their people -- and bring them home.