Guillermo Del Toro is known for his dark tastes in the occult, the supernatural and the weird, so when The Strain managed to find a home on TV everyone had high hopes for the adaptation of the horror novel series that Del Toro co-wrote with Chuck Hogan. And for the most part, we were rewarded with a good show. The Strain did have some poor writing and inconsistent pacing, but luckily the series has now come to a close with the fourth season.
Why luckily? Well, too often adaptations of self-contained stories are stretched across too many seasons, eventually fizzling out due to waning audience interest instead of ending on a high note. The Strain, however, was contained within a tidy four seasons, with a completely resolute ending.
The journey to that season 4 finale was pretty crazy. From ancient vampires, to an overrun New York, and even a few nuclear blasts – The Strain has been one of the most surprising television shows around. It’s been willing to push the boundaries of what ‘normal’ horror can do onscreen. Along the way, it strayed from the path laid out in the books in a few different ways, so for non-book readers here's a breakdown of how The Strain TV show's ending differed from the original story.
Let’s turn the clock back two seasons. When Kelly, Zach’s mother, was hunting for her son she found Ephraim and Nora in the subway tunnels, and she managed to infect Nora. The scientist decided to commit suicide by touching her sword against the subway tracks, electrocuting herself. It was a tragic moment, and was particularly shocking for book readers because Nora does not die in The Strain book series.
At the start of the final book in the trilogy, The Night Eternal, Nora left Ephraim for Vasiliy Fet, eventually having two children, one named Ephraim and the other called Mariela in honor of Nora’s mother. But since she didn't even make it past season 2, her relationship with Fet wasn't explored. Sorry, Nora.
Nuclear extermination seems like a great way of getting rid of the vampires (or a convoluted plot point, depending on who you ask). We’ve already seen the game-changing power that the nuclear bomb had during the end of season 3 - throwing up debris and blocking the sun. This allowed the Strigoi to enslave humanity, since they could now venture outside at all hours of the day.
The finale of the series takes place in a completely different location altogether from the ending in the books. In the original story, it’s revealed that thanks to some divine angelic origins (we’ll get to that) the Master was born on one of the Thousand Islands in Lake Ontario. The plan is formulated to acquire another nuclear bomb to try wipe out the Master, this plan succeeds as Eph, Quinlan and Zach set off the bomb, committing suicide for the greater good. Because Quinlan brought the ashes of the Ancients with him, the nuclear detonation kills the Master.
In the TV show, this ending is completely different (though it still involves a big explosion). Instead of heading to one of the Thousand Islands, the team lure the Master underneath New York, into the Third Water Tunnel. After the Master claims Eph as his new host, it's Zach who ultimately detonates the nuclear warhead and takes out the leader of the Strigoi - sacrificing himself in the process, but saving humanity.