Detectives Selles Morris, Judy Rolston, and Jamie Duignan are on a frantic search for a missing 17-year-old girl and her 2-year-old baby... and every minute counts. The baby is epileptic and without her daily medication she could suffer a fatal seizure. Meanwhile, Detectives Nari Isaakson and Jose Diaz race through some of the city's toughest neighborhoods looking for an 86-year-old man who vanished on the way to a Christmas party. He suffers from Parkinson's disease and dementia. With a blizzard barreling toward Chicago, detectives have only a few hours to find him.

• Bill Mondy