The episode begins with three students at three different locations sniffing a particular powder. We then see that they are appearing for their SATs. Cut to the empty library, where a student is seen sitting at a table with his head down; he is dead and there is blood all over his bag. The team arrives at the scene. Mac points at an object sticking out of his skull. He wonders why the boy in the lib on a Saturday and Don is tells him that the SATs were held this morning. Maybe he was studying late night and got locked in. Then how come the parents didn’t report him missing? Don finds the bloodied murder weapon lying under a table.
Next, Hawkes processes the crime scene and finds a lot of study material in his bag. He also finds dextro-amphetamines which are generally used to cure ADHT, attention deficit. He also finds an id and the victim is Luke Stevenson. The name sounds familiar to Mac and later we see Mac talking to Frank Stevenson, Luke’s father and an acquaintance. Frank tells Mac that last week Luke lost his friend, Nate, as he died because of drug overdose. Mac then tells him about the drugs found in Luke’s bag; but Frank tells him that Luke had no such problems. Frank is in denial that Luke could be on drugs. Lindsey is at her father’s and Danny calls to find out if she is fine. Her father, Robert, wants her to accompany him for a short drive. In the morgue, Sid too is upset about what happened to Luke.
Sid then retrieves a sharp piece of the mug from the skull and the toxicology reports are clean. But Nate’s reports shows extra 400 mg of dextro-amphetamines. What the drugs doing in his bags if he wasn’t using it? Maybe he was selling it and Mac wants to find out where he was getting it from. Mac tells Hawkes to process the plastic bag from Luke’s bag. Hawkes does the same and gets a print on it and it matches to Billy Wharton. Billy goes to the same school as Luke and he is an intern at the Mayor’s office. So, Frank was right. The drugs weren’t Luke’s. They then check Billy’s locker. He tells them that he thought Luke stole them. He says that he isn’t dealing in those pills; he is using them and he has a prescription for those.
He tells them that he carries them in a plastic bag as he does not want to advertise that he has ADHT. Mac knows that there was a fight between Billy and Luke. We see that Billy was confront Luke for copying from his exam and that leads to a tussle. Principal Connors broke up the fight and Billy did not rat out on Luke as he considered him as a friend. Mac wants Don to confirm the prescription and he wants his phone records checked. Next, Robert and Lindsey are fishing and Robert wants to know what Lindsey is doing at home. He tells her that he tried teaching Lindsey a lot of things but he feels he couldn’t do that as she had her own way of doing things. She tells him that she like her job and Robert asks her that hasn’t she seen enough.
Next, Danny tells Jo that the strand that he found on the body belongs to Melanie Rogers and she was dating Nate and was also a swimmer. The hand watch found on the scene also has her prints on it. Don and Jo go to talk to Melanie. Melanie tells them that Nate was addicted to those drugs and that he got those from Luke. When they try to accuse her of murdering Luke for being responsible for Nate’s death, she says that they are sick. She tells them that the watch was Nate’s and that she gave it to Luke thinking that he might like to have it. Adam is going through Billy’s phone records and he finds no contact between him and Luke. All his texts look like some basic algebraic problems. But Danny wants him to keep digging as Mac is not done with Billy. Hawkes is processing the murder weapon and Danny asks him if he found anything in Luke’s bag pack related to basic algebra.
Hawkes says that he found nothing like that and he asks Danny to check the bag again. He goes to get coffee. Danny finds a notebook with a page that has been torn from it. He checks the next page and sees that it has left behind the trace of the contents of the torn page. He processes it and finds out that it was a letter that Luke was writing to the newspaper where he was about to report the abuse of dextro in his school. So, looks like Luke wasn’t using it; he was about to blow the whistle. Don and Mac watch Billy and Billy is looking nervous. They see that Billy is supplying some kids with dextro and Luke was about to go public with this. And that was the topic of the fight between Billy and Luke. Just then they see Frank and he is about to enter the café that Billy is in.
Mac stops him and tells him that they aren’t sure yet if Billy is the murderer. Frank tells him that he found out that Billy goes to four different psychiatrists and fakes symptoms of ADHT and got prescriptions for dextro from all four of them. That is his source of supply. Mac tells Frank to go back and let them carry on the investigation and if Bill is guilty, they will catch him. Lindsey is in her room and she remembers the time she spent with her three best friends and how they dreamt of going to the same college and being together always. Adam cracks the messages. He tells Jo that the messages are requests for dextro sent to Billy and the answer is how much the students need. So, Billy is dealing. They check one message and they find that this one was sent by Melanie. Jo talks to Melanie once again.
She insists that she didn’t kill Luke. All she knows is that Billy said he would take care of it. Don arrests Billy. Lindsey is ready to leave. Robert offers to accompany her but she says that she will go on her own. Billy is being interrogated. He says he wants a trade for Mr. Connors. We then see how Connors confronts Billy with the dextro and Billy tells him that half of the school is using it. Lindsey goes to the prison and meets a guy and asks him how much money did he get out of the cash register as she wants to know how much were all those lives worth? The man says that he did not do it and this conversation is going to be futile. Mac confronts Connors and tells him that Billy spoke up. After he broke up the fight, Billy tells him that Luke knows that he is selling and is going public with it.
Billy threatens Luke that if he goes down he will take Connors along with him as this is his idea for churning out IVY League students. Connors tells Mac that he did try reasoning with Luke for keeping quiet as he could lose his job. But Luke didn’t want to listen to him and so he attacked Luke with the coffee mug. Connors is arrested. Next, Lindsey arrives to watch the execution of the man she visited in prison. His name is Daniel Cadence. He says that he is sorry for what he has done. And he is executed.
Cut to the flashback, we see that young Lindsey witnesses the murder of her three best friends at a restaurant which Daniel was robbing. Lindsey was hiding in the bathroom. In the present, Lindsey is back home and Danny is waiting for her. Lindsey returns to her life. The episode ends.