If you stir a cup of coffee carefully with a circular motion, the point at the center remains fixed under this motion.What happens if you stir in a more complicated pattern?Will there always be a point that returns to its original location? We will prove a two-dimensional version of atheorem that guarantees a fixed point for a continuous deformation of the surface of the coffee. The proof uses a clever counting argument known as Sperner's Lemma. The simplest version of this lemma says if your cat is inside when you go to bed and outside when you wake up in the morning, it must have gone through its little cat door an odd number of times.