Don't know how to finish my story!

Well Title says it all. My story is about this dog who moves to California were she meets these wonderful other dogs and she becomes friends with them. Well one day one of her friends gets kidnapped by these bad people. So her and her friends and these group of other dogs go looking for their missing friend. I'm on chapter 8 of it and I have no idea how to finish it! It's a short story. Any ideas on how to finish it? My mom wants me to finish it for "school".

Maybe their friend can be in a laboratory or used for dog fighting or was transformed or something? (:
I don't know; my ideas are stupid. xD

Thats a cute idea... ^^^