Vincent and Cat must work together to save J.T. 

A man from FBI Agent Landon's past may have answers about Vincent.

Cat hosts a celebrity cooking class and the theme is aphrodesiacs.

Tess tells Cat that Gabe is leaving the precinct, something Gabe didn't share with Cat. His work is done. He has cleaned up Joe's mess and the Department of Justice is taking him back.

Cat tells Tess that she doesn't want to get into a relationship so soon, and then takes a call from Vincent.

Vincent is keeping an eye out for Agent Landon so they can discover who killed her husband in the hopes she'll decide to go away. Vincent thinks if they find the gem, they'll find the killer.

Rebecca Reynolds tracked the gem in 1840 to a dungeon under Manhattan that was filled with artifacts and creature-like skeletons.

Tori is upset that Vincent is talking to Catherine again.

Tori wishes that Vincent would stop sneaking out of bed every night to talk to her. She wants him to say he doesn't want to go back to her but he cannot. He says all he wants to do is find the gem so he can stop them before Agent Landon finds out what's really going on. Meanwhile, Agent Landon is listening to Vincent outside his boat.

J.T. gets a Brady Wright Research Grant, including his own lab, worth about $500,000 and a party is thrown in his honor.

Gabe tells at he's still waiting for her, but moving on with his professional life. He wants to see what else is out there considering everything he has gone through with you know who.

Tori seems reluctant to believe there was a dungeon under the city.

J.T. is excited that he'll be going to see his new lab in a limo.

Tori tells Vincent he's all she has in the world, and Vincent acknowledges that but he says she changes him and they should take some time apart.

Cat suggests that Vincent talk to Tori because he tends to shut people out and it doesn't help to keep people guessing.

Tori arrives at the boat to find Agent Landon going through their things.

J.T. arrives at his new lab and he's shocked at the location. We also learn he forwarded all of his research files in advance. It appears J.T.'s lab is in the very dungeon Cat and Vincent are seeking and there is already an occupant, in a cage. J.T. is drugged.

J.T. wakes up chained to the wall. The man in the cage didn't mix the right serum, so they got J.T. to try to help him.

J.T. has been brought to the dungeon to replicate the serum Muirfield used to create beasts. The man who kidnapped him is the one who has been paying people to steal the gem.

The man holds a gun to the other man's head to force J.T. to try to make the serum despite his desire not to do it.

Vincent arrives at the boat to find Agent Landon bound and gagged. He and Tori argue.

Gabe and Cat talk about their relationship again.

Tess has news that J.T. has been kidnapped.

Agent Landon is now in the know about beasts, and she and Vincent agree to work together to stop the madness.

Cat and Gabe tell Vincent about J.T. and Tori learns about him decides to take matters into her own hands.

The prisoner tells J.T. the kidnappers know he has a beast and they are hoping to trade his life for the beast. Just then, Tori shows up and breaks J.T. free. The kidnapper has the gem and puts it on Tori.

The kidnapper knew Tori's father was a beast, but not Tori.

Vincent shows up to rescue J.T. again, and learns the kidnappers have Tori.

Vincent finds Tori and she's very weak. She says it's too late. Vincent says he should have protected her and she says she should have known he belonged with Catherine. The kidnapper then locks them both in the cage. Vincent beasts out and Cat shoots the kidnapper. Tori dies.

Vincent is worried that he puts everyone around him in danger, but now Cat wants to know about her own past, so she has to be involved.

Cat chooses Gabe.

Everyone thought the kidnapper was Barnes but it wasn't.

The man in the cell was Agent Landon's husband, Sam.

Vincent and J.T. share a scotch and talk about making the serum and who was at fault for everything that happened. That's when J.T. tells him about volunteering Vincent for the Muirfield experiment. Vincent just says you win and lets it go.

Vincent and J.T. toast Tori.