Robo, a beloved Great Dane, is tricked out of the embrace of his human family and then is horribly altered by a scientist who rebuilds him with technology never seen before. It leaves Robo a genius, almost immortal and with powers beyond explanation. But the suffering Robo experiences changes him--driving him insane with the sole mission to destroy all humans, especially those who have tortured and hurt dogs. Meanwhile, Blue, a scrappy alley dog, is trapped in a shelter, when she captures the attention of another scientist desperate to stop Robo from his path of destruction. Her mission: save human civilization and the packs of dogs she's grown to love.