In an aim to encourage purebred dogs, the government has introduced a heavy tax on mongrels, resulting in abandonment by owners and overcrowded dog homes. 13 year-old Lili loves her dog Hagen, but her father turns him out into the street. Whilst Lili is searching the city, Hagan, is left to defend for himself and discovers the cruelty of men. He joins a band ofstray dogs ready to mount a revolt against mankind. Their vengeance will be merciless and Lili may be the only person able to stop the war.