A little girl named Lily is forced to leave her dog Hagen with her dad, Daniel, when her mom moves to the USA. However, Hagen is not allowed in Daniel's apartment, and when animal control comes to take him away, Lily and Hagen escape. Hagen gets lost and is taken in by a man who trains him to fight, but Hagen escapes and joins a group of stray dogs who begin to rebel against humans.
The dogs, led by a dog named Load, start causing chaos throughout the city, attacking people and taking revenge on those who wronged them. Lily discovers that Hagen is with the group and tries to stop them, but they don't recognize her. Just when it seems like the dogs are going to attack, Daniel uses his trumpet to calm them down by playing Hagen's favorite song.
The dogs, including Hagen, lie down and are reunited with Lily and Daniel. The movie ends with the family happy to be together again, and the dogs no longer rebelling against humans.
Here are the key facts extracted from the text:
1. The movie begins with a scene where a little girl named Lily is playing with her dog Hagen in a park.
2. Lily's mother tells her to take Hagen to her father's house, Daniel, because she is moving to the USA.
3. Daniel is surprised to see that Lily brought Hagen, as he is afraid of dogs.
4. A man tells Daniel that pets are not allowed in the building where he lives.
5. Daniel tells Lily that Hagen will have to sleep in the bathroom if she keeps him.
6. Hagen falls asleep when Lily's friend plays his favorite song on the trumpet.
7. The next day, animal control comes to Daniel's house because his neighbors complained about Hagen's howling.
8. Daniel denies having a pet, but the animal control officer sees Hagen and tells Daniel he will have to pay a fine.
9. Lily's friend, Lee, takes her to her music class, but she hides Hagen in a closet because pets are not allowed at school.
10. Hagen gets scared and runs out of the classroom, causing chaos.
11. Lee's friend, Bruce, helps Daniel take Hagen to a shelter.
12. Hagen escapes from the shelter and meets a group of stray dogs.
13. The dogs take Hagen to a butcher shop, where they steal meat and get into a fight with the owner.
14. Hagen is rescued by a man who takes him to an abandoned place.
15. The man tries to sell Hagen to a buyer, but Hagen's friend intervenes and tells the buyer that Hagen is not a good fit.
16. The buyer takes Hagen anyway and trains him to fight.
17. Hagen fights in a dog fight, but escapes and meets up with his old friends.
18. The friends take Hagen to a shelter, where he is treated for his wounds.
19. Hagen gets aggressive and is put in a cage with other aggressive dogs.
20. The dogs escape from the shelter and start causing chaos in the city.
21. Lily and her father search for Hagen and find him with a group of dogs.
22. Hagen recognizes Lily's song on the trumpet and calms down, and the other dogs follow suit.
23. The movie ends with Lily, Daniel, and Hagen reunited.