One of the survivors is stricken with appendicitis, and Chuck considers a risky plan to get him to a hospital. Meanwhile, Ellen confronts Adam over his knowledge of the disease, and Ronnie tracks down Wiley and her baby.
Between is the story of a town under siege from a mysterious disease that has wiped out everybody except those 21 years old and under.
Wiley Day lives in Pretty Lake, and is pregnant when her father ishuged by the plague. Now she must cope with her coming delivery as well as try to keep the young survivors from panicking.