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.

• Bill Mondy