Bart wants Marge and Homer to buy Lou, but do not want to because it is expensive. At night, Bart starts hearing mooing and thinks he is hallucinating, but Lisa tells him it is just a CD of animal sounds that she started playing. Bart, Lisa, and two friends, named Compost and Solar Panel, go to the slaughterhouse at midnight to save Lou. They find Lou and see that he has been fed growth hormone pills and is much bigger, so they use a forklift to move him away from the slaughterhouse. They decide that they should take Lou to Mary's house because it is on a farm. The next morning, they discover that Mary's father is Cletus Spuckler.