Jack and his team investigate the case of a 28-year-old female marketing executive, Maggie Cartwright (ARIJA BAREIKIS), who seems to have simply walked away from her life, leaving everything behind. She was last seen by her doorman on the night she vanished, and her apartment appears intact, with even her purse and cellular telephone left behind. Her parents and colleagues reveal that she was a hard worker and a loner. She had just been spurned by her married co-worker, with whom she had been having an affair. A security videotape from her apartment building shows her walking away at night. Jack fears that the woman is lost forever--until a ransom note appears in her mother's e-mail account demanding one million dollars for her return.

Jack and his team search for an 11-year-old boy, Gabe (DAVID HENRIE), who disappears from a subway station en route to Yankee Stadium for what was to be his birthday celebration. After Gabe gets separated in the station, his frantic father, Bob Feldman (DAVID PAYMER), sees him boarding a subway train. He assumes that Gabe will get off at the next stop, but that doesn't happen, so Bob searches the ballpark before calling the police. By the time Jack's squad learns about the case, the boy has been missing for 16 hours. As they begin their investigation and gather information for their Day of Disappearance timeline, the agents learn that what initially seemed to be a case of a missing child and possible abduction has become a very different scenario: The boy may have run from his dad on purpose.

As a couple, Duncan (KYLE SECOR) and Emily (STACY EDWARDS) Muller, cross to their car after a day of shopping, Duncan realizes that he needs to go back into the store to retrieve his credit card. After Duncan walks away, his wife's car speeds off, leaving a bystander, Doug Dunsmore (RICK RAVANELLO), injured. Witnesses say an unknown assailant forced the frightened Emily into the car and drove away. Jack and his team are called in to find the missing woman. But as they interview Duncan, along with the witnesses and the couple's acquaintances, to construct their Day of Disappearance timeline, the detectives realize that this case may involve more than just a random kidnapping.

The agents' job is harder than usual because they must find a woman, Eve (KAITLIN DOUBLEDAY), who changes her appearance to suit whatever modeling or acting job she is seeking at the time. No one seems to know Eve well, including her roommate, who files the missing persons report when she notices that Eve's beloved cat has not been fed for days. Jack and the team find a half-packed suitcase in Eve's room but few other clues. The investigation becomes more illuminating when the squad members interview people associated with the modeling agency that Eve occasionally worked for. Meanwhile, Jack is haunted by an old case that he still cannot solve for a grieving father, Chet Collins (recurring guest star CHARLES DUTTON - "Roc," "The Corner").

Jack and his squad search for a young man, 17-year-old Andy Deaver (JARED HILLMAN), who was last seen by the charismatic headmaster, Graham Spalding (CONOR O'FARRELL), of Spalding Academy, the private boarding school Andy attends. When Andy is reported missing, Jack immediately suspects the headmaster. Spalding is a former veterinarian with no credentials for his current job except that his father founded the school. And it appears that his relationship with Andy, as well as with other boys in the past, was unsavory. As Jack gets closer to implicating Spalding, he fears that he won't be able to get enough information from Spalding in time to find Andy alive.

Jack and the team search for a New York businessman, Patrick Kent (ERICH ANDERSON), who disappears after he checks in for a routine airline flight home. During the investigation, the agents are shocked to discover that Kent has been leading a secret double life--but that his father-in-law, Noah Ridder (PHILIP BAKER HALL), has him under surveillance by a private investigator for another reason entirely.

Jack and his squad search for a toddler, Abby, who was snatched from a park playground while playing with another child. Abby is the daughter of prominent New York Assistant District Attorney Angela Buckman (MARIN HINKLE) and her college professor husband, Matthew (JOHN MESE). As the investigation proceeds, clues implicate suspicious people in both parents' lives. But when none of the suspects proves to be the culprit, and a ransom demand is made, the team members suddenly realize that they are focusing on the wrong aspect of the case.

Jack and the team search for a teenager, William Hope (DEMPSEY PAPPION), who goes missing in a very bad neighborhood after a confrontation with a local bully. Considered a good kid, William was living in a foster home after 18 months on the street and seemed destined for a better life when he disappeared. The squad discovers that his older brother, Aaron (N. NEKO PARHAM), who was recently released from juvenile hall, visited William, despite the fact that his foster family forbade Aaron from being in their home. Jack and the others then learn that William was seen getting into a car with Aaron immediately prior to disappearing, and they fear that the good kid may have gone bad.

The team investigates the disappearance of Anwar Samir (DARIUSH KASHANI), a Saudi Arabian medical intern who became upset when his boss refused to write a letter of recommendation for him, and his girlfriend declined his marriage proposal. Anwar is a hardworking and well-respected doctor whose every move becomes subject to interpretation after he disappears. His desire to work at the Centers for Disease Control to study infectious diseases, his girlfriend's lack of knowledge about his career ambitions and even the books in his apartment suggest that he might have a hidden connection to terrorism. As Jack coordinates the investigation with the Joint Terrorist Task Force (JTTF), he discovers that samples of a virus are missing from a biotechnology company where Anwar once worked. Meanwhile, the team thinks that Martin--who is convinced that Anwar is a terrorist--may be more concerned with impressing the JTTF supervisor than with the truth.