Cat and Vincent's French honeymoon is cut short after J.T. realizes that a blogger's sensational story on beasts may lead to Vincent's exposure.
Cat and Vincent must protect an heiress whose identity has been exposed due to a DHS hack while also tracking down the beast black-market buyer.
Vincent and Cat's pursuit of the beast bounty hunter leads them to an underground fight club. J.T. struggles to tell Tess the truth about his job.
As she starts her new DHS job, Cat wonders if she's pregnant. Meanwhile, Vincent hunts down a dangerous lead, and J.T. tries to outsmart the bloggers.
After falling during a fight with the mercenaries, a feverish, guilt-ridden Vincent hallucinates about how Cat's life might be different without him.
Cat and Vincent follow a lead from Hill and search for Vincent's former commander, a known beast killer, while also being pursued by a TV reporter.
Cat must prove to a suspicious DHS that she can still be trusted, while the now-fugitive Vincent uses himself as bait to get inside a private army.
Cat continues her deception at the DHS, as Vincent, playing the betrayed outsider, works to convince the bounty hunters to add him to their crew.
As the TV reporter confronts Cat, Vincent tries to glean information about the beast buyer while planning his own capture with the Graydal team.
DHS hunts for Vincent at Graydal, unaware that Braxton is holding him captive in order to run a series of "beast tests" on him for the secret buyer.
Cat's plan to exonerate Vincent by bringing in the second beast goes awry, forcing the couple to consider new identities and life on the run.
When Cat learns that DHS suspects the imprisoned Vincent is behind an impending terror attack, she vows to find out who is trying to set him up.
Before leaving New York for their new life together, Cat and Vincent pledge to find Braxton and his prince accomplice and stop the terrorist attack.
As Cat and Vincent try to embark on a normal life together, federal agents pressure them to help hunt down a mysterious new threat.
Cat and Vincent vow to find out who's experimenting on innocent people, while J.T. gets a visit from someone who wants his serum.
Two married DHS agents join Cat and Vincent in the hunt for a killer, J.T. makes a startling discovery and Tess weighs a big opportunity.
When a heart intended for a wealthy transplant recipient disappears, Cat and Vincent both set out to find it, but for very different reasons.
While Cat works a robbery case with a new partner, Vincent heads upstate on hospital business. But spending a day apart invites trouble.
With wedding preparations in high gear, Cat and Vincent navigate tricky family situations. Meanwhile, the experiments take on a scary new dimension.
Cat comes up with a plan to lure a would-be assassin out of the city, but Vincent doesn't like it. Heather's job interview takes a surprising turn.
As Vincent and Cat head to the altar, J.T. and Tess try to keep their news secret, and a new danger emerges.
Vincent makes a disturbing discovery at the morgue, Cat resolves to play by the book at work, and J.T. tries to change Heather's mind about destiny.
Tess tries to protect J.T. from Liam, while Cat and Vincent zero in on one of Julianna's former patients.
Liam tries to recruit Vincent for a mission, Cat investigates Liam's ties to a powerful family, and J.T. makes a mind-boggling discovery.
After hatching a new plan to stop Liam, Cat and Vincent bring in a familiar face to help. Meanwhile, a revelation about beasts has Cat worried.
In the season finale, Liam lays an elaborate trap, Vincent faces the fallout from his vigilante past, and Cat tries a desperate final ploy.
When she was a teen, Catherine Chandler witnessed the murder of her mother. Cat would have been killed too, but someone, or something, saved her.
While Cat investigates the mysterious death of a rising young ballerina, Vincent senses that her understudy is hiding information.
Cat and Tess arrest a Bosnian immigrant named Iris, whom they suspect killed an immigration judge for deporting her brother.
Vincent revives a 19-year-old victim who was beaten and left for dead inside a dumpster. As he lies in a coma, Cat and Tess question his father.
On a late night walk with JT, Vincent stops a convenience store robbery, only to learn that a surveillance video captured his good deed.
Cat wonders whether Vincent is keeping his distance due to the kiss she shared with Evan at her birthday party.
Cat investigates the murder of a college fraternity brother, and JT examines Vincent to find the cause of his increasingly frequent blackouts.
While Cat and Tess investigate the attempted murder of a teen pop star, JT suspects that Catherine is triggering Vincent's fugue states.
A dateless Cat confides to Vincent that she wishes he could go with her to her father's wedding. But she learns something surprising at the reception.
Worried that he'll be exposed as the Beast, Vincent leaves an unconscious Cat in the road so that Evan can get her to the hospital.
Cat focuses on her physical recovery after being shot. But she can't return to duty until she gets the approval of a police department therapist.
Cat tells Tess and Heather that she's ready to move on with her life in spite of her feelings for Vincent, whose identity she's still protecting.
Vincent wants to reconnect with Cat and vows to regain her trust, but she doubts she can trust him again after he left her for Alex.
Heather catches Vincent kissing Catherine, who decides that the best way to disarm Heather's curiosity is to have Vincent over for dinner.
A new assistant district attorney arrives at the precinct, suspicious that cases involving the vigilante are being mishandled.
Vincent and Cat take their relationship to a new level, but their intimate moment is shattered when Catherine is called to a crime scene.
Cat tends to Vincent's wounds when Tess shoots him, and JT shoots Tess with a tranquilizer gun to stop her escape.
Heartbroken by Cat's relationship with Vincent, Evan reveals the location of the Beast's lair to Muirfield operative Kyle.
Gabe reveals to Cat that Muirfield experimented on him as a child. Against Vincent's wishes, Cat teams up with Gabe to track down a server farm.
On the anniversary of her mom's death, Cat bumps into Gabe at the gravesite and discovers that Vanessa smuggled Gabe out of Muirfield as a child.
After a pregnancy scare, Cat and Vincent ponder what kind of future they could have. Gabe is under guard at a hotel after an attempt on his life.
While under the influence of Gabe's pills, Vincent can't beast out -- and the effects will be permanent if not reversed soon.
Three months after Vincent Keller was abducted by Muirfield, Det. Catherine Chandler is reunited with him -- but not in the way she planned.
While attempting to learn more about Vincent's mission, Cat gets kidnapped by him, prompting Tess, J.T. and Gabe to come together to help Cat.
Catherine and Vincent track a mysterious beast while keeping their individual agendas from each other. Meanwhile, Heather has a revelation for Cat.
In his quest to track down a suspected beast, Gabe enlists Vincent's help, but Vincent quickly takes matters into his own hands.
When Cat attends her high school reunion, she uncovers more of her past than she anticipated. Meanwhile, Vincent meets up with an old military buddy.
Cat confronts her birth father about the mysterious role he's played in her life, while Vincent has to neutralize a high-profile beast.
True feelings are revealed and secrets are outed when Gabe and Tori join Cat, Vincent and Cat's father, for Thanksgiving.
Vincent and Cat find themselves at odds on how to deal with agent Reynolds, and this forces Vincent to wonder if he is more beast than man.
To prevent Vincent from further injury, Cat helps protect Tori when her life is threatened, revealing a new, unexpected mystery.
Vincent goes on a national talk show to reveal he is still alive, while Cat dives into an undercover case for FBI agent Dana Landon.
A group of criminals holds Cat, Tori and Tess hostage at the precinct, and Vincent must risk exposing his identity to rescue them.
Cat and Vincent must work together to save J.T. when he gets kidnapped. Meanwhile, a stranger from FBI agent Dana Landon's past surfaces.
When Cat has to work with Vincent on Valentine's Day, she's forced to evaluate whether she wants to be in a relationship with Gabe.
While searching for some of Gabe's missing acquaintances, Vincent sees what his life could have been when he visits the hospital where he interned.
Torn between her current boyfriend and her ex, Cat finds her decision further complicated when she and Vincent end up in a compromising situation.
To prevent Sam from destroying a large group of people, Cat and Vincent are forced to revisit a romantic destination from their past.
When Vincent is arrested for murder, Cat and the team work to clear his name but realize they have a bigger problem when they learn who turned him in.
Cat's sister drops by for a surprise visit just as Gabe suspends Cat and Tess from the squad in an effort to force Vincent out of hiding.
Cat and Vincent take agent Knox's offer to extricate themselves and lead normal lives -- but forces out of their control conspire against them.
Desperate to start over with Cat, Gabe tries to woo her by arranging a romantic date. She has plans of her own, however, about how to save Vincent.
Cat searches for a way to thwart Gabe and finds her answer in an unexpected place: her ancestor's journal, which yields a troubling solution.