Criminal Minds: Evolution – Swimmer’s Calculus

By: Mariah Thomas

Following the aftermath of Gold Star, we pick up six months later. The episode opens up with the unsub’s (Clayton Royal Johnson) point of view. We watch as an unsuspecting victim is sprayed with something to make him pass out. As the unsub attempts to drag his body, a police officer pulls into this dark parking lot. He checks on the passed out man and is approached by the unsub. He is able to convince the officer the man is his older brother and he can safely get him home. “You almost died tonight, pal. Get home safe,” are the ironic last words the officer tells the victim as he leaves. 

Next, we see a group of young friends sitting around a bonfire at a beach in Maryland. A young woman, Chrissie (Daisy Wang), ventures off to go swimming and is followed by one of her friends who is subtly harassing her. She stands her ground in a playful, independent banter. This is cut short when the two see a body washed up on shore. As an officer takes Chrissie’s statement, we hear David Rossi (Joe Mantenga) announce the arrival of the BAU. The team swoops in while Emily Prentiss (Paget Brewster) introduces the team. JJ (AJ Cook) reveals this may be the work of a serial killer they have been tracking. Tara Lewis (Aisha Tyler) confirms the signature of puncture wounds is present on the body and it officially becomes a BAU case. “Can you stop him?” The officer asks as the team looks up in unison with a “do you know who we are?” look on their faces.

Back at the BAU offices, Tyler Green (RJ Hatanaka) is officially a training agent. He looks over photos of the current case as Luke Alvez (Adam Rodriguez) and JJ quiz him to see if he is a fit for the BAU. They also tease him for the fake gun he has to carry until he completes his training. Until then, he gets to carry a knife.  As they continue their playful banter, Rossi storms out of his office and slams the door. Luke reveals that Rossi has been being questioned by the FBI’s Internal Affairs department. In his questioning session, it is revealed to be about Elias Voit’s (Zach Gilford) attack in last season’s finale. The previous episode ended with Voit being brutally attacked by other inmates in the prison’s laundry room. Rossi has been consistent in his stance of having no involvement in this attack. A recording of Rossi telling Voit that “gen pop is no place for serial killers” is played, which is being taken as a threat higher up. It is clear now Rossi’s job is on the line to prove his innocence in potentially ordering an attack. He gets the IA agent to turn the recording off and tells her “If I wanted Elias Voit dead, he would be dead. And he’s not dead, is he?” before leaving the room. 

Garcia (Kirsten Vangsness) watches over Voit in a hospital bed when Prentiss walks in. Garcia expressed empathy for Voit saying he seems “non psychopathic” in his comatose state. Prentiss reveals he has suffered a traumatic brain injury. She is at the hospital to pick up an incident report on Voit’s attack to hopefully help Rossi. Garcia jokes that even in a coma, he is still all up in Rossi’s business. Garcia and Prentiss talk about the logistics of Voit’s attack and how it is astounding he is still alive.

Tara and JJ walk the halls of the bau as they share a conversation on their personal lives. JJ’s mother in law is due in town soon for her son’s birthday. Tara’s father wants to meet her girlfriend. As they finish their conversation, they join Tyler and Luke. They catch up on the case at hand and reveal the victim has swimmer’s calculus. Tara explains how this has to do with the pH of water. From this, they are able to determine the victim’s drowned in a swimming pool and not the ocean. There is a cut away to the unsub filming his latest victim fighting for his life trying to stay above ground in a pool as he grows tired. 

Prentiss brings the file from earlier to Rossi who wants nothing to do with it. He tells her that since Voit has been in a coma, his hallucinations have stopped and he wants nothing to do with him. Prentiss reminds him they have worked too hard to let Voit take his job. They profile the scene through photos and Rossi is able to have an idea investigators may have missed. 

JJ and Tara grab their lunches as they head to continue talking the case out with Tyler and Luke. They all throw different ideas out as they profile the facts they have at hand. Garcia calls the team over with an update, “it’s not demure or mindful” she jokes. A beach rental property company is something all victims have in common. The team decides to deliver the profile to the company itself in hopes of gaining access to who viewed the victim’s information. With the help of Tara’s girlfriend, Rebecca Wilson (Nicole Pacent), they gather the company heads. They are all hesitant to give up any information but they are able to seek out one man who is willing to help. He is scared to lose his job, but Luke and Tyler use their military backgrounds to persuade him. Once he reveals his fear of being caught, Garcia walks in. 

A family of three celebrate the father’s birthday on an empty beach. As they take photos to remember the Estes family outing, the unsub can be seen behind them in photos slowly getting closer. He sprays them with his drug mixture that knocks them unconscious. Back at his house, the unsub holds a gun at the family and instructs them to get in the pool. When they refuse, he shoots the father, Curtis (Eddie Mills). The mom, Kristi (Jade Harlow) tells her daughter, Vivian (Tate Moore) to get in and takes charge to do anything to keep her child safe. Small actions from having her swim behind her and stopping her from taunting him. It is clear she has a plan. 

Rossi pulls Prentiss out of a meeting to show her his findings. Voit was able to hide the shank he had to defend himself in the fight. It tells them he knew they were coming.  Luke approaches Garcia about her visits with Voit. She pulls him into her office to explain. She said she looked into his eyes and saw an ember of a soul. She believes there is some humanity left in him. She further explains she visits him to hopefully see something good again and blames her empathy. 

Back at the unsub’s house the women attempt to make a run for it when he is distracted. However, he quickly catches them and starts shooting. In retaliation, he closes the pool cover on them and throws the body of their dead husband/father in with them. The mother and daughter duo struggle to keep their head above water. 

Back in the BAU, they discover the missing family we have been seeing glimpses of may be connected. By now, they have found the unsub’s identity. When the unsub was 10, he killed his family by drowning them in a pool. His father was a lifeguard and abusive to him for not being able to pass his swim test. They believe this family reminded him of his own. 

The BAU suit up and head out to the house to hopefully rescue the current victims. As they pull up to the house, the unsub begins shooting at the pool cover. The mother is shot in this stand off. Before shooting himself, the unsub smashes the pool opener. Using his handy knife, Tyler cuts open the cover and Luke dives in to save the two women. Tyler gets his field assignment and he reveals he is going to miss the team. “It’s just five years” he reasons before they all “hmm.” It’s five years before the jump to SSA, and then another ten before he can join the BAU. 

Prentiss tells Rossi the team’s latest case may be connected to Voit’s network. It is circumstantial as of now, but seems to be the same software. When Prentiss opts for the technical route, Rossi stops her and asks if she buys what she’s selling. She tosses down the file and says “No.” They know deep down, Voit is involved. The episode ends revealing Voit has woken from his coma.