The episode begins with Vincent lying on the ground after being shot by Tess. Cat arrives and tells him that he will be fine. She tells Tess to call an ambulance. Tess tells her that the beast tried to attack her. Cat tells Vincent that he will be alright. Tess is shocked on learning that the “beast” is Vincent Solanski, the guy Cat was dating. Vincent says that he doesn’t want an ambulance and that he would use a knife to remove the bullet. Tess calls for backup, but the radio doesn’t work. She then rushes to call for backup. Cat follows her.
Tess is about to get out of the tunnel, when Vincent pulls her back. Cat is surprised to see Vincent and he tells her that he heals quickly. Cat tries to explain things to Tess, but she is too freaked out to understand anything. JT arrives and tranquilizes her. JT tells them that they should run before Tess wakes up. Vincent thinks otherwise. He says that Cat should try and convince Tess about their situation. JT tells Cat that her other friend, Evan is on Muirfield’s payroll. They are baffled. Vincent tells them that the most important thing is to deliver the DNA samples to the lab, so that Evan can confirm that he is dead. JT takes the can and leaves. Cat tells Vincent that Tess is a cop and the only way to convince her would be by putting together all the old cases and building a strong case to prove that Vincent only killed when he had to protect someone.
At the precinct, Joe notices that Tess and Cat haven’t arrived. He thinks that they might be celebrating the ‘take down’. Gabe arrives and doesn’t look all that convinced about the whole thing. He is also pissed that Joe has called in a press conference. JT arrives at the lab to meet Evan. He says that he is excited to see that the “creature” is caught. Evan is not too comfortable with JT being around and he tells him not to touch anything in the lab. Cat arrives and tells him that she needs some of the earlier case file, so that she can write down her final report. JT takes this opportunity and switches the DNA samples. Cat is about to leave the precinct and Joe tells her that she has some answering to do. He takes her to the press conference. In the tunnel, Tess wakes up and Vincent tries to explain things to her, but as expected, she doesn’t believe a single thing.
At the precinct, Gabe is highly suspicious of what is going on. He notices that Tess isn’t around. He questions Cat and Cat is totally nervous. She tries to leave the precinct, but Gabe insists that they should go and check on Tess. In the tunnel, Vincent and Tess are waiting for Cat. Vincent once again tries to explain things to Tess. He goes to get some granola bars for Tess and Tess tries to attack him with the tranquilizer and runs. Vincent gets her and tells her that she needs to protect Cat. He begs her to talk to Cat before she decides to do anything else. Vincent lets her go. At Tess’s house, Gabe looks around and feels that Tess’s behavior seems extremely odd. He tells Cat that he suspects Tess and the whole “got the guy” story. Cat wonders why an ADA is so driven by this case. Gabe chooses not to answer and leaves.
Cat is about to drive away when she sees Tess. She tells Tess about everything Vincent has done over the years. She also tells her that the “beast” who saved her, was Vincent. She tries to explain that the world is a better place with Vincent in it. Tess tells cat to turn Vincent in. She tells her that she will cover for her if she brings Vincent in. Cat tells her that she cannot do that and she leaves. Tess calls for Joe, and leaves a message saying that “they have got the wrong guy”. At the lab, JT and Evan see that the DNA is a match with the beast. This means that the beast is really dead.
Next, Cat arrives in the tunnel and tells JT and Vincent that Tess is going to turn them in. They need to get out of there as soon as possible. Later, Tess arrives with the two “trigger happy” cops in the tunnel. They are also carrying a weapon that is used on animals. Tess is suspicious and tells them that she did not mention that their guy is a beast. She realizes that these two men know more than they are saying. She hits them and tries to run. One of them shoots Tess and she falls down in the water and her body floats away. The cops then continue with their search for Vincent. They are not worried about Tess’s death because no one in the precinct knows that they are in the tunnel. Later, we see that Tess is not dead, her bullet proof vest saved her life, but she will soon drown in the water. She cries for help.
Vincent senses that there are others in the tunnel. They see the two cops. Vincent tries to distract the cops, so that Cat can sneak past them. They tase Vincent. On the other hand, Tess is drowning and she is screaming for help. Cat and Vincent manage to kill both the cops with great difficulty. They then spilt up to find Tess. Vincent hears Tess’s screams and checks the drain. He pulls off the grid and pulls her out. Tess apologizes for what she did.
At home, Tess and Cat are having Bourbon and we see that they are back as friends. Joe calls Tess and she tells him that cat saved her life. At the precinct, Joe loses his cool on Gabe. He tells Gabe that Tess was in the sewers and called his men for backup and they never showed up. He says that Cat went looking for Tess and she saved her. Gabe apologizes on his men’s behalf and tells Joe that he will never see them again. Next, Gabe goes to the sewers to find answers. He sees “fresh” scratch marks on the walls and concludes that the beast is still alive. JT arrives at the lab with beer. Evan is not in a mood. JT realizes that this has got something to do with Cat. Evan admits that whatever he did was for Cat.
JT feels awkward and tells him to celebrate this moment because the beast is dead. Evan agrees. At home, Vincent is happy that Cat and Tess are friends again, and that Tess is on their side. He tells her that he needs to find JT and search for a place to put all their stuff. They kiss. Evan is walking towards Cat’s apartment, and sees Cat and Vincent kissing on the fire escape. Vincent leaves. Evan is bewildered. Cat doesn’t notice Evan and goes back in. Evan smiles because he now knows the “truth”. The episode ends.