Vincent and Cat face the fact that they've lost control of their secret and may have to go on the run. Vincent also realizes that he needs to face his past; and Cat worries about what they may lose.moreless
Vincent undergoes a series of tests arranged by the mystery buyer in order to not be exposed; and Cat, JT and Heather try to exonerate Vincent.
Vincent and Cat strive to return normalcy to their lives despite the threats posed by a beast bounty and DHS manhunt; and Tess takes a risk by shielding Vincent from a reporter.
Vincent goes undercover with an operative whom Cat learns is an assassin; and Cat tries to prove to DHS that she can still be trusted.
Vincent and Cat regroup in their effort to bring down the beast hunters. To that end, Vincent tries to infiltrate a private army while Cat attempts to obtain information at work while hoping no one discovers her ulterior motives.moreless
Vincent and Cat learn that another nemesis is out to get Vincent; and their relationship is endangered when they wind up on opposite sides of the law.
When Vincent and Cat are forced into hiding due to his being someone's target, he wonders what life would have been like for her without him in it—and gets a glimpse of just that.moreless
Cat investigates who's after Vincent and suspects that she may be pregnant. In other events, Vincent follows a lead that puts his life in jeopardy; and J.T. is kidnapped in a case of mistaken identity.moreless
Cat and Vincent's newlywed life is upended by lurking danger and they soon find themselves in the fight of their lives.
Cat and Vincent hunt a black marketeer of beasts; and try to protect an heiress whose identity was revealed.
In the Season 4 premiere, Vincent and Cat's wedded bliss is short-lived when J.T. brings them the news that someone is trying to expose the identities of beasts.
In the season 3 finale, Cat and Vincent are forced to work together as a couple - as never before - if they hope to defeat Liam. Liam intends to do everything he can to expose Vincent as a beast in order to destroy their love.moreless
Liam's history spurs Cat to dig into the Ellingsworth family's past; Vincent and Cat realize that they may need their secret weapon to defeat Liam; and JT develops a theory on how to save himself.moreless
Vincent agrees to help Liam retrieve evidence that could expose both of them. Cat, meanwhile, digs up disturbing information about Liam's family history.
Cat and Vincent set out to capture Liam; and come across information that could help them do just that. In other events, J.T. and Tess work to confirm that J.T. is serum-free.
Vincent, Tess and Heather try to boost Cat's spirits after the events of her big day leave her doubtful that they can defeat the threat.
It's Cat and Vincent's wedding day, and everyone is determined to make sure nothing threatens to ruin the event, including any superhuman experiments.
Using the ruse that they plan to elope, Cat and Vincent attempt to lure an unstoppable assassin out of town to protect love ones. Tired of police protection, J.T. asks Tess to help him track down a lead. Heather does her best to focus her attention on her new job.moreless
J.T. arranges a surprise bachelor party for Vincent, but the fun is cut short by a sniper who's out to end Vincent and Cat's interference with the super human experiments. In other events, Cat's family comes to town for her bridal shower and Cat visits her imprisoned father to ask for his help.moreless
Cat is assigned to a new partner; and comes to suspect that Bob and Carol are working to separate her from Vincent. In other events, JT learns that his newfound healing ability comes with a high price.moreless
Cat and Vincent see a therapist about their relationship; and Cat investigates a wealthy transplant recipient whom she suspects may be behind the mysterious experiments.
Cat and Vincent team with married DHS agents on a case; J.T. thinks he may possess super powers; Tess contemplates a career move; and Heather makes a suggestion that could make her big sister's life a little easier.moreless
Vincent moves in with Cat as the two investigate a new lead to track down who is behind the super-human experiments. While trying to impress Tess' brothers, J.T. finds out there might be side effects to the medicine Agent Thomas used to save his life. Heather returns to town with a surprise announcement.moreless
With the couple finally in a happy place, Vincent considers proposing to Catherine. But when she discovers a case involving someone turning innocent people into superhuman beings, the two have to find a way to stop them. Meanwhile, Tess is upset over J.T. stalling his recovery because of his bewilderment over how he was able to survive.moreless
Cat fears Vincent must die in order for Gabe to be stopped in the Season 2 finale.
Gabe tries to woo Cat by taking her on a romantic date.
Agent Knox's offer to Cat and Vincent for a normal life together is accepted, but influences out of their control work against them.
To force Vincent out into the open, Gabe suspends Cat and Tess from the force. In the midst of all this, Heather shows up for a surprise visit.