An unexpected guest brings old conflicts to the surface, dividing our heroes, threatening the group's trust. With questionable new intel in hand, they launch a make or break final assault on the Master.

Reeling from loss, our heroes regroup. To defeat the Master, they must locate him first. Our heroes devise a new plan to track him through human collaborators, beginning at the blood farm with someone Dutch knows all too well.

His health failing, Setrakian ignores Eph's warnings, pushing himself to the limit in his quest for victory and revenge. Fet and Quinlan race back to Manhattan, while the Master seals off the city and prepares to eliminate them all.

Fet and Quinlan have to figure out how to get the nuclear bomb back to New York, while a desperate Eichhorst draws near. Love struck Zack tries to learn more about his new crush, but makes a devastating discovery.

Quinlan and Fet discover that stealing a nuclear warhead isn't easy when they encounter an unexpected enemy. Eph and Alex concoct a new weapon to use against the strigoi. Frustrated with his seclusion, Zack discovers a love interest.

Fet strikes hard at the heart of the strigoi army while Justine embarks upon a risky mission to drive the strigoi out of Manhattan once and for all. Gus and Angel fight for their lives and their freedom but are faced with a moral dilemma.

The Occido Lumen is gone. Stolen. Setrakian and Fet race to recover it. Gus and Angel try to hide a secret houseguest while avoiding a police sweep, and Quinlan's thirst for vengeance is revealed.

As the strigoi turn New York into a war zone, survivors and the military must pull together and fight.

Gus helps the Guptas get across the border; Fet, Nora and Eph look all over the city for Dutch, who's in a life-or-death struggle with Eichhorst; Setrakian meets a familiar face while searching for the Occido Lumen.

Justine takes drastic measures to counter a surprise invasion. Nora and Fet perform a useful mission while Eph and Setrakian face off against an old foe.

Setrakian and Fet use Fitzwilliam's info to attack the Master, but a mysterious new player arrives. Dutch receives a surprise guest. Eph returns to NYC frustrated but energized to go after ...

Eph concocts a plan to make and distribute a bioweapon. Gus realizes Angel can be an unlikely ally, and Kelly comes after Nora and Zack.

Stock reporter discovers how the master plans to use WiFi to recruit conspiracy theorists to his horde of minions.

Vet and Dutch grow closer on a mission to make sure neighbourhood buildings are clear. Meanwhile, Eph and Nora perform experiments on their new patients; and Kelly begins her search for Zack.

Agent Ephraim investigates new cases about Master in NY City.

Eph and Fet recon for an all-out assault that Setrakian assures them will finally kill the Master. Gus aligns himself with a strange new force, one that may swing the fight in an unforeseen direction.

Dutch returns with a plan to broadcast Eph's warning about the vampiric plague. However, they face a new threat when Eichhorst launches his own attack against the pawn shop. Palmer receives...

Setrakian leads Eph, Fet and Nora in the hunt for the Master's lair. Left behind at the pawnshop with Mariela, Zack risks his safety for Mariela's sake.

Eph investigates Kelly's disappearance and struggles with what he finds. Dutch pursues a plan to retaliate against Palmer, and Fitzwilliam makes a surprising choice.

Eph races to safeguard his family, only to learn that Kelly is missing. Dutch reveals her role in Palmer's plan, and Gus is forced to make a difficult decision about Felix.

After discovering the potency of ultraviolet light against the strigoi, Setrakian gains a new and unlikely disciple. A quick trip to a Brooklyn convenience store turns into a deadly all-night siege.

Setrakian, Eph, and Nora formulate a plan to track down the Master using Jim as bait. Eichhorst and Setrakian's pasts are revealed. At the Luss home, Neeva struggles to protect the children...

After warning Kelly to leave the city with Zack ahead of the spreading plague, Eph is arrested by the FBI. Eichhorst has one final job for Gus, while Setrakian realizes that the coming ...

With Nora gone, Eph reluctantly joins Setrakian's quest in hopes of gathering enough evidence to warrant a citywide quarantine. Fet encounters the unexpected inside the subway tunnels, and ...

A secret autopsy demonstrates the bizarre progression of the mystery virus, prompting Jim to make a startling confession. Eph and Nora race to find the father of the youngest victim of the ...

Eph and Nora fight to save Captain Redfern's life before coming face-to-face with the horrifying effects of the virus. A spike in rat attacks signals Fet that something inexplicable is ...

The four survivors begin manifesting strange symptoms, but Eph and Nora's attempt to quarantine them is thwarted as the disinformation campaign begins. Meanwhile, in jail, Setrakian ...

When a commercial airliner lands and stands silent, CDC agent Ephraim Goodweather investigates the plane to find that the passengers are infected by a vile plague.