Even though Mesh's goal is to illustrate mathematical concepts, it is at its heart a story.  In Mesh, the lead character is discrete geometry. 

Starting with the ancient Greeks, we discover the harmony and beauty in discrete geometry.  When that harmony was used to describe curves or smooth structures such as the motion of the planets, it was inadequate.  When our character's tragic flaw was revealed, calculus became the tool with which to tackle this shortcoming.  For centuries, the ancient study of discrete geometry would be regarded as an antiquated, overly simple view of the world.