You shouldn't take lost animals and just leave them somewhere.
Mark finds a lost dog wandering around his neighborhood with no collar or ID and takes it in for the night.
Mark needs to find something to do with the dog he found.
Mark takes the dog in his truck to the local animal shelter, in hopes that the original owner will come to claim it.
Mark puts the dog in his truck and drives to an empty field before letting it loose.
The dog is thrilled when its owner arrives to pick it up.
The dog wanders around the unfamiliar terrain, and is stressed out and scared.