The episode begins with three ballerinas performing in the studio. One of them walks towards the empty auditorium and turns on the lights and starts dancing on the stage. A feather falls on her and she looks up and screams; she sees the body of another ballerina hanging from the ceiling and her hands are tied in front of her. The team arrives on the scene. The victim is Ellen White and she is nineteen years old. The ballerina who found the body is Alexa Holdman. Ellen was Alexa’s understudy. Hawkes says that the COD is asphyxiation and maybe it is not the rope that killed her.
Looking at the bruising, the team confirms that somebody strangled her and then hung her up. But, why hang somebody who is already dead? Danny goes through Ellen’s stuff. And he also sees several ropes similar to the one used to hang Ellen. He lifts off some prints as well. And it is the pullet system that was used to hang the body. Don arrives and declares that the other ballerinas and the Director of the show, was there from 5-8 and Ellen went for a break at around 5.30 and never came back. So someone else was in the building who wasn’t supposed to be there. Hawkes says that the TOD is around 6. Next, Mac goes to meet Christine. He tells her about the aphasia. Christine tells him that the most endearing thing about him is his pride, but that is also his weakness.
She wants to know if she can live with that. In the morgue, Sid tells Jo that Ellen was bulimic. But she was also self- mutilating. The killer went straight for her neck and there are no defensive wounds. Hawkes tells Danny he cannot find anything from Ellen’s phone that shows anyone would want her dead. Danny finds gun powder on the rope that has gun powder from before the civil war. Lindsey becomes a victim of a lab prank and she has circular marks around her eyes. She thinks Adam did it. But Danny and Hawkes are suspects too. At the same time she is working n the murder of a Jane Doe and the weapon used in this murder is a gun made in the 1800s. There is black color gun powder residue made from this bullet wound.
It is similar to the one Danny found on the rope. So the GSR found on Jae Doe matches to the one found on the ballerina; doesn’t make sense! Two completely different methods and no signature left. Next we see a guy aiming a gun at a girl and the cops arrive and arrest him. It is the same used to kill Jane Doe. Jamie goes in to interrogate the guy. He is Sam Cross. He says he doesn’t know about the murders. He saw Jane Doe lying dead and he took her jewelry. He saw the gun beside her and took it. But he knows nothing about Ellen. There are a lot of chemicals found in Jane Doe’s body similar to those present in an anti-depressant but Lindsey hasn’t seen this sort of a combo before. Catherine arrives to meet Mac and she says that he could share anything with her.
Lindsey arrives and Cat leaves. Lindsey tells Mac that there is a drug called Trioxiphil that was found in Jane Doe’s system and it is still in the human trial mode and waiting for FDA approval. When she called the company, she learned that the company is working with a select group of psychiatrists. One of them has a patient whose description matches Jane Doe. The psychiatrist, Carly is called in and she says that the victim’s name is Lisa Weston. Carly tells them that Lisa had bipolar disorder and she doesn’t recall hearing about Sam. She also says that Lisa came from a privileged background and she was very guarded when it came to men. Mac asks her if she mentioned about Ellen to her. It turns out that both the dead girls were Carly’s patients.
Sam’s alibi checks out and Adam finds out that the gun was bought online by Carly. They go to Carly’s office. And she is gone. Maybe she never reached there at all. Don tells Jo that there are Polaroids related to Ellen’s murder on her desk. Mac figures out a clue. He says that White was killed at the conservatory with a rope. And Lisa, the Scarlet was killed at Hell’s Kitchen with a revolver. This looks like a clue. Mac pulls out a game board of CLUE and says that there are four more potential victims. So, according to the game, the scarlet moves first, then the mustard and then white. So what happened to the mustard? Maybe there is a body they don’t know about. Mr. Green would be next and Jo thinks that they need to be concentrating on Carly’s male patients.
The next victim is found on a golf course (green); he is Shane Simmons. He used to work part time at the ball room and had to wait back late to get the course ready for the next day. Carly knew his routine and she attacked him when he was about to leave the store. But Don thinks that not many woman of her size could drag a guy with Shane’s size through such a distance. Mac feels she might have hired someone. Lindsey examines the white thread like think found on Shane; it turns out to be the whiskers of a snow leopard. So how did that get on Shane? They talk to Robby Hull, the guy who takes care of the leopards. He says he rents his car and Lindsey thinks that someone who rented his car could be the killer.
The guy who rented the car is Steve Davis and he has been Carly’s patient since he was 13. He suffered from OCD and depression and she stopped treating her two months ago as Steve fell in love with her. And they also find out that he is off his meds. They find out that Steve rented the car from 11-2 am. Lindsey checks the car and finds that there are bloodstains that match to Shane’s. The team goes to Steve’s house and they find Carly. She tells them that she doesn’t know where Steve is. They then see the game board and the next target is Plum at the library. Jamie sees that he has been keeping a track of his victims’ schedules and they have one for Plum too. Hearing the schedule, Mac infers it is a Professor and Carly knows that it is Clayton’s schedule. The team goes to the library.
They ask the students to leave quietly. But after searching for a while they don’t find signs of either of them. They realize that Hastings library wasn’t the first library and so they go to Chelsea University. And Hawkes tells them that the place where the library stood initially now has a hall. They arrive at the hall and find Steve standing over the professor with a knife. He has already hurt Clayton. He runs up the stairs and Don and Jamie follow him. Jo calls for the meds. Mac gets hold of Steve. At the station Steve is shocked to learn that Clayton, the doctor’s fiancé is alive. He tells them about how he confessed his love for Carly and how she turned him down. He says that Clue was the game they played to break the ice when he first went to see Carly.
She was Peacock and he was Mustard. He then broke into her office and picked up the patients. He did all this to hurt Carly. Case closed. Next, Danny arrives at the office with flowers for Lindsey. He wants to take her out for dinner. She realizes that Danny is the prankster. He says he was supposed to tell her but she was too pissed; hence he didn’t. She smiles and accepts the flowers. Mac goes to meet Christine and tells her that he loves her. The episode ends.