You shouldn't keep a dog that isn't yours.
"Fern has recently taken in a stray dog and is now seeing ""lost dog"" posters containing photos that look like him."
Fern wants the dog to be safe.
Fern calls the number on the posters and meets with the owners of the lost dog.
Not knowing what his owners are like, Fern keeps the dog safe in her posession.
Fern realizes that the owners care deeply about their dog and return him to them.
The dog and his owners spend the rest of their lives missing each other.