Eph and Nora experiment on their newfound patients. Fet and Dutch grow closer as they clear out the neighborhood buildings, and Kelly begins her hunt for Zack.
Gus and Vaun wage an attack on Palmer as Eph struggles to connect with Zack. Councilwoman Justine Faraldo vows to bring her extermination policies to the other boroughs.
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.
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 the one person responsible for killing his friends.
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.
Eph and Dutch work together to thwart the Master’s greatest ally. Justine runs into trouble with the Mayor while Setrakian tracks down the real owner of the Lumen.
Setrakian and Fet battle for possession of the Occido Lumen, and gain a surprising new ally. A massive attack imperils Eph, Nora, and Zack's escape from New York.
Eph and Nora work on a biological weapon to kill the strigoi, and Setrakian risks the lives of the entire group to find information about a closely guarded secret text. The Master begins the next phase of his own plan, by creating a terrifying new breed of creature and placing them under the control of Kelly.
Eph and Nora finally see their lethal virus in action. Fet takes the security of Red Hook into his own hands while Dutch and Setrakian set off for Staten Island to question Fitzwilliam, Palmer's former body guard.
Eph changes his appearance to leave the city while Nora is left as the reluctant parent for Zack. Dutch and Nora make a deal with Justine to secure Fet’s release from jail.
Eph must protect Zack against a surprise intruder into Red Hook. Gus convinces the Guptas to make a difficult choice. Fet and Setrakian set out to acquire the Lumen but discover they are not the only potential buyer.
Dutch fights for her life against Eichhorst as Fet, Nora, and Eph frantically search the city for her. Setrakian confronts an old acquaintance on his search for the Occido Lumen, while Gus helps the Guptas escape across the border to safety.
The strigoi are evolving, becoming faster. Smarter. Eph struggles to improve his failing bioweapon while trying to work through the emotional fallout of the abduction of his son, Zack. As Setrakian and Quinlan attempt to crack the Lumen’s deepest-held secrets, Fet helps a Navy SEAL team in a deadly mission: search for the Master through the underground tunnels of New York.
The Master’s offer to return Zack plagues Eph as he considers taking the deal. Dutch reunites with an old group of friends but begins to question if her safety is better with them or with Fet, Eph and Setrakian. Palmer strives for answers to Setrakian’s secret strigoi blood treatments and discovers he may have a way to acquire it.
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.
Things have changed. The infection enters a new phase. Fet wants to celebrate, but Setrakian and Eph are worried there's more work to be done. Justine conscripts a new, unwilling army in the fight while Eichhorst angrily lashes out with a plan to strike back.
New information from the Lumen forces Setrakian to seek help from his lifelong nemesis, Eldritch Palmer. Eph’s new experiments to understand strigoi communication seemingly take him to the brink of madness while Fet is on a mission to discover strigoi movements across New York City.
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.
Setrakian offers hope in a new plan to trap the Master while Eph and Dutch seek out the Master’s “voice.” Palmer, frail and close to death, needs Setrakian’s access to the white to hold up his end of their bargain. Fet suffers a devastating personal loss revealing a long-hidden family secret.
The Master’s voice proves to be more powerful and potentially fatal than Eph or Dutch anticipated. Fet and Setrakian track down the cargo from the Egyptian vessel and realize they may be in over their heads. Quinlan strikes a deal with the Ancients, but a last minute betrayal proves deadly.
NYC is falling. Eph and Dutch frantically race to finish their new device to stop the Master before the city is overrun. Justine, Gus, and Angel fight in one last stand to stop the spreading virus. Palmer extracts vengeance for past wrongs but may have crossed the line.
Humanity teeters on the edge of destruction. The Master finally reveals himself, initiating the end game of a battle in which there can be only one winner. Eph, Fet, Setrakian, and Dutch must overcome their personal differences in a last-ditch effort to vanquish the strain.
When a plane lands in New York City with everyone on board dead, Dr. Ephraim 'Eph' Goodweather, head of the CDC’s Canary Project, and his team are called upon to investigate. What looks at first like a mysterious viral outbreak might be the beginning of something infinitely more sinister.
The four survivors begin manifesting strange symptoms, but Eph and Nora's attempt to quarantine them is thwarted as the disinformation campaign begins. Setrakian receives a surprise visit from an old – a very old – acquaintance.
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 happening deep below the city. Released from jail, Setrakian begins his own merciless plan to stop the spread of the disease.
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 plane tragedy, but someone unexpected beats them to it. Ansel, in the grip of disease, takes desperate measures to protect his family.
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. A medical emergency threatens Palmer's master plan.
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. Setrakian realizes that the coming eclipse is the tipping point for virus infection and the beginning of the end.
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 while encountering a mysterious stranger whose help she may not want.
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.
Eph races to safeguard his family, only to learn that Kelly is missing. Dutch reveals her role in Palmer’s plan. Gus is forced to make a difficult decision about Felix.
Eph investigates Kelly’s disappearance and struggles with what he finds. Dutch pursues a plan to retaliate against Palmer. Fitzwilliam makes a surprising choice.
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.
Dutch returns with a plan to broadcast Eph’s warning about the vampiric plague, but they face a new threat when Eichhorst launches his own attack against the pawn shop. Palmer receives a special visitor. Gus gears up for the on-coming fight but discovers there’s another mysterious factor involved.
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.
The fourth and final season opens when out of the ashes of humanity’s nuclear war, Night Eternal has begun. Haunted by the atrocities committed by his son, Eph abandons NYC for Philadelphia. His solitude is cut short when he encounters new fighters who rekindle his drive to fight back. Tasked by Setrakian, Fet and Quinlan search for a new means of stopping the Master.
Imprisoned as a subject in a strigoi breeding program, Dutch is desperate to escape and find Setrakian. Gus recruits his cousin for the inside job that will put his gang at the top of the new world’s underground economy, but Creem is suspicious of his business partner’s ambitions and a CDC team investigates the outbreak of a mysterious illness that mirrors vampirism.
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.
Dutch is forced to make a deal with Desai while she plots to escape a strigoi breeding facility. Eph and Alex seek to uncover the dark secrets behind the Partnership’s new plan but face the repercussion of their last attack. Gus and Creem face off against a gang encroaching on their turf.
Fet and Quinlan are hot on the trail of a convoy carrying their prized nuclear weapon. Eph and Alex search for clues to uncover the Master’s plan for the ultimate fate of the human race. Dutch is trapped by a familiar enemy, yet encounters an old friend as well.
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.
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.
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.
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.
In the series finale, Quinlan devises a desperate plan, but the costs are enormous. Eph wrestles with his conscience, Fet undertakes a suicide mission, and Dutch and Gus dig in for battle as humankind makes its final stand against the Master and his Strain.