Maggie Cartwright appears to have simply walked away from every thing in her life, having left everything of hers behind. Later a ransom note appears on her mother's email list demanding a million dollars for her safe return.

Eleven-year-old Gabe Freedman is separated from his father on the subway to Yankee Stadium.

When a man leaves his home in the morning with his daughter to take her to school and then to open his dry-cleaning store, but they both of they never make it there .

Jack and the team search for a pregnant woman, Kathy Dobson, who disappeared from a hospital before being told that she has serious complications. As the detectives race against time to find Kathy, their investigation gradually reveals that Kathy's seemingly happy life actually hasn't been going very well. She is eight-and-a-half months pregnant and, under the tight control of her husband Paul, has withdrawn from her family and friends. Paul's brother Ritchie, who has been following Kathy and providing Paul with addresses she visits, lists a woman who may be affiliated with an ""underground railroad"" that helps battered women. When the team members find the woman, they learn that she has been assaulted by Paul—but she still refuses to lead them to Kathy.

The team investigate a disappearance of a flight attendant who may have been having a relationship with one of the pilot's.

With the aftershocks of Sept. 11 and man named Barry , who lost his wife that day and then his job soon after. The man lashes out at her former boss an employment-agency owner. Blaming her for his wife's death and his own failure to find a job, Barry kidnaps the woman for ransom.Then he demands the money be exchanged at a bookstore, but when the cash is delivers Berry is provoked and takes the store's patrons hostage. Among them is Samantha,and given Jack's affection for her complicates the negotiations.

When the team tries to plot a strategy after they find out that Samantha has been shot and that she might be critically injured in the hostage crisis situation. Jack makes a deal with Berry so that Sam can get help and Jack goes in there and takes Sam's place.

A school bus is abducted by kidnappers who demand more and more for ransom.