Simon is a very old cat. He has had a wonderful life chasing butterflies, eating houseplants, and even playing the piano. His family adores him and they do everything they can to keep him comfortable. Now that he is old, Simon feels useless. Then one day his family drops something small and soft on his tummy-a tiny kitten! There is so much the kitten needs to learn about the world, and Simon is happy to teach him. Suddenly Simon has a lot to do!