Heart lives a hard and lonely life in the village of Ash Grove until she finds a scarred, skinny mare in the forest. She adopts it and names her Avamir, after herself. Heart notices that the mare is going to give birth and she is so excited. However, when the foal (baby horse) is born, it is very weak and looks ugly. Heart's guardian, Simon, decides to sell them to be slaughtered and be made into soap. Can Heart find a way to protect them?