The episode begins with a ghost hunter, Owen Webber and his team, Doug and Carrie, trying to hunt the ghost of Walter Sims, a gruesome serial killer. Carrie goes to check the room where Sims killed the little boys. Owen and Doug go to the hanging room, which has a lot of metallic hooks (used to hang meat) hanging from the ceiling. Doug tries to summon Sims’s spirit. He pulls out a knife from his bag pack, similar to the ones that Sims used to butcher the boys, and tries to lure the ghosts. At that moment, the metallic hooks start clanking, and it is seen that the knife has disappeared. Doug starts screaming.
Owen and Carrie rush to the room only to find Doug’s body hanging on one of the hooks. Carrie screams. Moments later, the team arrives at the crime scene, the Zimney meat shop. Brass tells Finn that twenty years ago, the security guard, Walter Sims, who lived in a trailer on site, kidnapped seven young boys over a period of nine months and brutally murdered them. Later, Sims died in the same place. Now Doug is killed in the exact same way. It looks like Walter Sims has risen from the dead. Finn and Sara manage to get the body down. They notice the camera lying next to the pool of Doug’s blood. It looks as if somebody moved it, there is blood under the camera and the memory card is missing. Morgan processes Owen, and Greg processes Carrie.
Carrie tells Greg that they were shooting the video to upload it on the internet. Carrie also tells Greg she felt a strong presence in the room. She shows Greg the amulet she wears around her neck for protection. Owen admits that he took the memory card from Doug’s camera. Morgan tells him that he needs to hand it over. Thomas Pope, the property manager, arrives and tells Brass that his firm is developing the property. He tells Brass that the firm gave the “ghost hunters” permission to shoot. He also tells Brass that he always had a bad feeling about this place. In the morgue, Robbins tells Russell that the killing is the exact duplication of the original case. Russell thinks that the copycat killer did his homework well. Robbins tells him that the autopsy reports of the boys were heavily guarded and nothing was made public.
He then points out to the ‘S’ shaped incision made by the killer. S for Sims. Greg and Morgan go back to the crime scene and discover a room, which is a shrine for the seven young boys Walter Sims killed. It has their photos, and a lot of toys around the photos. Some of them look as if they have been there for ages, whereas some of them look new. Greg feels a little uneasy, but doesn’t say anything. Morgan finds an earring amongst the toys. Finn and Sarah examine the slaughter house and recreate Doug’s murder. They figure out that one man could have easily killed Doug. They then spray the luminal liquid to check for blood on the ground. There is a lot of blood and footprints. People walking in and out, without realizing that they are walking on blood that isn’t visible to the naked eye.
They find a set of footprints going in the opposite direction. It stops at a wall in the hallway. Sarah pulls out the murder weapon which was hidden in the wall. Nick shows Russell the recording from Owen’s camera. They notice that his camera shut off for 98 seconds. Sarah arrives with the murder weapon and tells Russell that it has Owen’s prints all over it. They bring in Owen for interrogation. They show him the knife, and Owen admits that it is his knife and he brought it along with him to the slaughter house. He tells them that he had nothing to do with the murder. Carrie arrives to meet Owen. She finds Greg and tells him that Owen did not kill Doug. She also senses that Greg too felt some presence in that room. She knows that Greg’s grandmother was a psychic, and he shares her gift.
She removes her amulet and gives it to Greg. She tells him that he will need it. Hodges tells Henry that since they don’t have any pictures, they will use the camera’s electronic voice recorder (a device used to record ghost voices) to get the location of the killer. He says that they need to go back to the crime scene. Russell introduces Scott Tunnicliff to Finn. Russell tells her that Scott is an expert in the Sims murder and he wrote a book. Since his uncle held a good post in the Department, he managed to get access to the sensitive material in those cases. He gives them his reference journals. Finn notices a woman in all the pictures. Scott tells her that the woman was a trial groupie. Finn points out that she is wearing an earring similar to the one Morgan found in the slaughter house.
Scott also tells Finn that he felt that Sims had an accomplice who lured the kids into the vehicle. At the slaughter house, Hodges determines that Owen isn’t the killer. Henry looks at the computer screen and determines that there is some low frequency infra sounds present all over the place, which cannot be heard by the human ear. He explains that many times the infra sounds create the feeling of some sort of presence, what people call “ghostly presence”. He also says that the low frequency waves cause different sort of vibrations in our body. He thinks that they should track the source of the sound. They manage to track the source; it is a large exhaust fan and Henry turns it off. At that moment, they hear a woman’s screams. They rush towards the sound and they find Carrie lying dead on the floor.
They also find a bloodied baseball bat lying next to her. They call the team. Morgan and Greg are at the shrine. They collect the toys so that Hodges can examine them. Greg tells Morgan that when he was young, he was a psychic. Morgan finds it difficult to believe. Greg finds an EVP recorder. It could be Carrie’s, which got tossed when she was hit. They play the recording and hear some laughter, it sounds like small children laughing. At the precinct, they bring in Monica, the trial groupie for interrogation. Monica tells them that she goes to the warehouse to meet Walter and ‘her’ boys, the family that Walter created for her. She tells them that one of her boys killed Doug and she witnessed it. Greg finds out that the laughter was pre-recorded. This means that someone played a pre-recorded laughter after killing Carrie.
Henry examines the toys and finds a DNA on every single one of them. It is a man’s DNA and it is the same DNA that was found on the front seat of Sims’s car. Russell tells Nick that all the murdered boys’ DNA were found on the back seat of the car. So, this means that Sims had an accomplice, and Carrie’s and Doug’s killer is someone who knew Sims’s MO really well. Russell suspects Scott. Later, Nick tells Russell that Scott’s alibi checked out. Russell has a new theory. He tells Nick that it is possible that Sims could have abducted and eighth boy and forced him to be his accomplice. When the cops arrested Sims, he ran away. Nick gets the missing report files from the time Sims started killing the boys. They match the prints from Sims’s glove box to the prints found on the toys and Carrie’s murder weapon.
It is a match to Thomas Pope, the manager of the firm that owns the slaughter house. Greg goes to the slaughter house to find some answers. Pope arrives, and Greg thanks him for giving him permission to go inside once again. It is seen that Pope is hiding a weapon under his coat. He asks Greg what he is trying to find. Greg tells him that he is not sure. At that time, Pope’s phone rings, and the ringtone sounds like the laughter of small children. Greg realizes that it was Pope’s ringtone that was recorded on Carrie’s EVP recorder. Greg arrests Pope. At the interrogation, Pope admits that he killed the ghost hunters because he was scared that they would talk to the ghosts of the boys and learn his secret. He admits that he is Jonathan Harris, who helped Sims with his murder when he was 11 years old.
He says that he tried too hard to erase his past and build a new life, with a new identity, but the ghosts of the boys always tormented him. Pope says that he did not want the ghost hunters to talk to the ghosts and that is why he killed them. Case Closed. Next, Morgan meets Greg and apologizes for disbelieving his ‘psychic’ theory. Greg tells her that he too feels that there is nothing of that sort because when he was at the slaughter house with Pope, none of the ghosts gave him even one sign to indicate that Pope is their killer. Morgan asks him out for breakfast. Greg removes Carrie’s amulet from his neck, hangs it in his locker, shuts it and leaves. On their way out, Greg’s locker opens on its own. Morgan and Greg are shocked. The episode ends.