Delia Rivers is a local NYC investigative reporter who was working on a dangerous story that involved Freddy Cattan, a nightclub owner who is a reputed drug dealer--however, no law enforcement agency had thus far been able to make anything stick against him. Yet Delia's recent news reports had been able to make a dent in Cattan's organization, thanks to an unknown source that has appeared in Delia's newscasts hidden in shadows with his voice electronically altered. When Delia abruptly disappears, her case is given to Jack's team--but there is a twist. Delia was a colleague of Jack's, and just before she disappeared, she left an urgent message for him to call her back. Unfortunately, by the time Jack got her message, Delia had already vanished.

Delia's message to Jack indicated that she was seeking information, but not what for. When Jack and Sam check out Delia's job, her producer tells them that Delia was working on a case that she claimed would outlaw the death penalty in New York. But nobody at the station knew what it was, for Delia kept it a secret, and all of her notes on her sources written in cryptic code. Jack figures the best way to find Delia is to uncover her source, and since it would have to be somebody with intimate knowledge of Cattan's operations, a likely candidate would be Diego Mondesi, Cattan's right hand man. When Jack and Danny pay a visit to Cattan at his club, he tells them that Mondesi is away in Tokyo on business--something that neither agents believes, and their skepticism is right on the money, for Mondesi soon turns up dead. A further complication for Jack is the arrival at FBI headquarters of his wife and young daughters. Jack's wife gives him the unsettling news that a strange man approached her and the children and threatened them in so many words. Her description of the man matches that of one of Cattan's hired thugs. The case now takes a sharply personal turn for Jack as Freddy Cattan, the ruthless drug lord suspected of causing the disappearence of Delia Rivers, now appears to have targeted his family.

The Source is a superb example of the twists and turns that occur in a typical episode of Without A Trace. The storyline is as tight and taut as they come. And while Freddy Cattan proves to be a particularly slippery eel for the Missing Persons Squad to catch, the tactics they finally use against him prove to be ingenious. Another interesting aspect of this episode is that we finally meet Jack's family. And the long, hard look that Jack's wife gives Sam (while she and Jack are speaking, unknowing they are being observed) is very telling. The producers have been dropping little hints about the private lives of the Squad members all season, and having Jack's family threatened serves a duo purpose: it creates drama in the main plot of the episode, as well as deftly pushes a major sub plot into the spotlight.