Season 4 picks up nine months after Zack pulled the trigger, unleashing a nuclear winter that allows the Strigoi to walk by day, finally fulfilling the series’ ongoing Holocaust parallels with the vision of a world reborn to serve the Master and his bloodsucking ilk. Humanity is forced into “The Partnership,” a one-sided union with the Strigoi in which the humans regularly donate blood in return for food and medical help, trudging terrified through the streets with identifying badges wrapped around their arms while armed Strigoi guards hiss and sneer from the sidewalk. Naturally, the food and medical aid are only enough to keep the walking Happy Meals pumping nourished blood, but the remnants of humanity are in no position to argue. The Justines of the world are gone, there is no Staten Island safe haven and no government support on the way, and the laws of nature have forsaken humanity without the sun to offer them respite from the Strigoi assault.
The Strain's final season is focused and fierce, with opening episodes that plant seeds for stomach-turning strigoi showdowns and heartbreaking character collisions all the way down the line to the vampire saga's highly anticipated finale.