When Ruff is ready to fetch his Sunday morning bone, his master accidentally throws it over the fence into their neighbor, Slim's yard. Ruff goes to search for it, but when he finally notices it, it falls into a tree, which leads him underground and into a cave. The cave is full of bones and he isn't sure which one is his. When he finally does, it's too late and a caveman tosses it out of the cave, which leads Ruff into the clouds in the sky digging for it. It falls into a jungle, and then into a sunken ship in the ocean. Ruff then sees a ladder that goes into space, and finally lands on a bone planet. He at last finds his bone, and an alien takes him back home in a UFO space-ship. Once he makes it back home, his master congratulates him, only to throw his bone yet again.