A young man, Will, leaves his fancy apartment building. He holds the door for a neighbor who asks him to hold her baby while she gets her mail. The doorman hears shouting outside and runs out to see Will sitting bloody on the sidewalk with a man standing over him. He gets up and walks away and disappears.
Sam comes into work cooing about her kid. Medina is back from DC, with a case, Will's. Will's dad is a counterfeiting agent with the Secret Service and Will went to school with Medina's son.
16 Hours Missing
Jack and Danny visit Will's parents, Mark and Lisa Duncan, who are extremely organized with forms and lists ready. They've put out an Amber Alert already. Danny hands them a sketch of the man who assaulted Will but his dad's sure it was a counterfeiter, possibly some Belgian ones he's investigating.
Flashback to Will quitting an internship at his dad's office and his dad getting mad at him. Will telling his dad he's a hypocrite and doesn't care who he hurts.
At the office while Sam looks into the Belgians Elena reports that Will has been cutting school.
Martin checks in with Medina and tells him thanks but no thanks on the No. 2 offer. He's not comfortable with the circumstances.
Viv and Elena visit the school to talk to his best friend, a girl named Darby. She doesn't recognize the sketch. With her mom standing there, Darby says she doesn't know why Will was ditching. She says Will idolizes his dad.
Flashback to Darby presenting him with floor tickets to a concert, but him turning them down because he can't afford them. He says his dad won't give him money for anything unless it's for school or health, but that he's cool in his own way. She says a few weeks later he showed up with hundred dollar bills but wouldn't tell her where he got them.
Off the phones, Danny has discovered Will stole the counterfeit money from his dad's stash for presentations from home.
Martin gets a call. The receipt from Will's backpack is a password from an Internet cafe near Will's house.
Jack tells Sam he turned down the Wall St. guy's offer. He decided to stick around and "see what opportunities opened up."
19 Hours Missing
Sam and Jack at the Internet cafe. A woman there, Lilah, recognizes his photo, but not the sketch.
Flashback to Will at the cafe being confronted by a jock, telling him he gave him the wrong file. She says the jock was in there a few days earlier and it seemed fine.
20 Hours Missing
At the office a tech goes through the Internet cafe computer. He hacked into the school's server, downloading tests.
Jack visits the headmaster, who is surprised Will was cheating. Jack shows him a sketch of the jock. Jack says the school swapped out dummy tests, which could have been why the jock was mad.
23 Hours Missing
They interview the jock, Brett, who says he doesn't recognize the sketch of the guy who beat up Will. When they threaten his academic record, he 'fesses up, saying Will gave answers away.
Flashback to Brett discussing poor cheating strategies with a classmate and Will overhearing and offering to get the tests, saying everybody cheats.
Brett says four other kids flunked the same midterm he did.
Medina confronts Jack, saying it's not about finding people, it's a power trip for him. He's mad Jack talked to the headmaster without going to him.
Sam has ID'd the attacker, brother of a counterfeiter.
24 Hours Missing
Elena and Viv visit the guy, Gene Fuller, who says his brother was small time and he just wanted to discuss it with Mr. Duncan. He says he didn't hit the kid, he helped him up when someone else hit him.
Flashback to the guy from the cafe confronting Will over his sister, Lilah, saying she's not right for him.
Gene ran because he's on probation and didn't want problems.
Danny shows the Duncans photos of Lilah and Terrance, the Internet cafe people. Jack asks Mr. Duncan what he's hiding. Mrs. Duncan tells him to tell the truth because Will found out that his dad was having an affair.
Flashback to Will coming home and not wanting to talk to his mom. He tells her he saw his dad with a woman a week before he quit his internship. They were hailing a cab together.
Flashback within a flashback to Mark canoodling on the sidewalk with a young blonde.
He tells his mom he's sorry, but she says he must be confused and doesn't know what he saw.
Jack asks Mr. Duncan for the name of his mistress.
Viv checks with Medina. Connecticut police caught Lilah and Terrance coming back into town. She tells Medina that Will knew his dad was having an affair.
Martin with Terrance. Sam trying to intimidate Lilah.
Terrance says he hasn't seen Will since the sidewalk. They were at a cabin in Connecticut.
Lilah says Will didn't break up with her. She's pregnant.
Flashback to Will talking to Lilah after his beatdown, saying they should talk. He doesn't want to be a coward like his dad. He tells her he loves her and wants to do right by her.
She says they talked for hours and he called a cab and left. She says her brother didn't do anything to Will.
29 Hours Missing
Martin and Elena check the building where the cabbie said he took Will. They see blood on the stairs and a spot where a rug is missing, complete with drag marks.
30 Hours missing
Forensics teams go over the apartment.
Vivian tells Danny that Mr. Duncan leases an apartment in that building. Danny interviews him while Medina and Jack watch. Jack doesn't think he did it.
Medina says the case hit a little close and might have clouded his judgment.
Vivian has footage from the security camera out front. It shows Darby going in after Will.
They confront her with the photos. Her mother says she wasn't involved while Jack asks Darby if she killed him. They ask for a DNA sample.
She says he wouldn't help her. She followed him from the Internet cafe. Flashback: She wants the English lit test, but he tells her he's not doing it anymore. She freaks out as he stands on the stairs. She grabs for him and he falls down the stairs backwards landing, dead, at the bottom.
Jack asks who helped her move the body.
Flashback to her mom showing up and helping her.
Darby cries, upset that her friend is dead over a stupid grade.
They find his body in the Dumpster out back.
A montage (set to a mournful Rufus Wainwright tune) shows Medina breaking the news to the Duncans, Sam telling Lilah and the Duncans meeting the mother of their grandchild.
Jack drops the case report off with Medina who says it was pointless because nothing they did would have saved him. Jack says there's no amount of training that can prepare you for what people can do to each other. He says taking the job home with him doesn't help him sleep, but it gets the job done.