The Disappearing Diaspora

Daelin High School alumni are returning to Daelin for a mega-reunion involving five graduating classes. Those grads who left Daelin for better opportunities than were available in their small Georgia town are often called the diaspora, the scattered ones. The first alum taken is Captain Riley McDonough's high school crush, Lucy Hendrickson. Riley and Daelin PD's finest are on the case, including Dorie MacAvoy, former reporter turned Liaison Officer. However, Dorie and Ross's pregnancy teeters precariously on viability.
Will Dorie and Ross's child survive?
Which alum will be abducted next?
Why are they being taken?
How will the police find the disappearing diaspora?