Detectives Pam Childs and Selles Morris search for a 14-year-old girl who has been snatched by a 19-year-old with possible gang connections. The hunt leads detectives to a hotel district at the edge of town, through gang territory and across the state. Meanwhile, on the hottest day of the year, Detective Pat Riley searches for a missing 66-year-old man with serious neurological problems. Riley fears the man may be armed. The clock ticks as the thermometer tops 100 degrees. Riley must find the missing man before he succumbs to the heat--or gets into real trouble.

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--without her daily medication, she could suffer a fatal seizure. Meanwhile, a potentially deadly blizzard bears down on Chicago as Detectives Nari Isakson and Jose Diaz race through 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. Detectives must find him before the storm paralyzes the city.

With Mother's Day approaching, Det. Bob Berent meets with another anguished family. The son and daughter of a 48-year-old Iraqi immigrant returned from work to find her gone. She has no ID and no money, and her children believe she may have delusions that she can return to Baghdad. Det. Nari Isakson joins a search that spans from forest preserves to O'Hare Airport. Meanwhile, Detectives Pam Childs and Joe Struck hit the streets in search of a 48-year-old woman. Her two grown daughters fear she is the victim of foul play. As Childs and Struck interview witnesses and possible suspects, they uncover startling new evidence: it's clear that someone knows something.