WARNING: The following article contains spoilers for Netflix's Kingdom and HBO's Game of Thrones.
Netflix's Kingdom unfolds against the backdrop of a zombie outbreak in 17th-century Korea. After the king falls ill, the sinister General Cho attempts to ensure the throne pass to the unborn child carried by the queen (his daughter), rather than to the crown prince. To enact his plan, Cho uses a "resurrection plant" that must be administered to keep the monarch alive.
However, that transforms the king into a zombie, whose attacks on his medical staff spread the infection throughout the land, with one of his victims is eaten by cannibals days later. As the series progresses, the king hunts Crown Prince Lee Chang, who gathers support from ill-treated peasants. They need a solution for the zombies, which hide from the daylight like vampires, and believe the prince can lead the way. In the Season 1 finale, however, the prince can only focus on one problem at a time, and as he gears for a showdown with Cho's forces, Kingdom plucks its big twist straight from HBO's Game of Thrones.
The prince's coalition is strengthened by one of Korea's most famous warlords, General Ahn. With that alliance, the prince now has an army capable of defeating Cho's men, who have left the kingdom and come to Ahn's province on the fringes of the capital. The prince knows it's all-out war, but Cho is surprisingly playing a mysterious waiting game, presumably intended to provide the zombies time to attack the resistance at night, and thereby diminishing the enemy ranks. However, the night passes quietly.
As the alliance forces prepare to launch the first volley the next day, one of the prince's physicians, Seo-Bi, wanders into the hidden Frozen Valley, where she finds the plant her master used on the king. It's a purple flower once thought to be only a myth, used to reanimate the dead. Realizing Cho used it to make the prince's claim illegitimate, as Lee Chang was born to a concubine and not to the queen, Seo-Bi begins to piece together the general's scheme. However, the kicker comes when she discovers that, despite it being broad daylight, zombies are now roaming freely. She deduces that it's not the daylight they hid from, but rather the heat. And now, on the first day of winter, the undead are liberated.
That results in a zombie horde attack the prince's army. Cho, apparently experienced with zombies from his old war days, smartly maneuvered the pieces into place so as many of the undead as possible were lured onto the battlefield, only to then go hunting for the closest source of food -- the alliance forces. The final shot of the season is the prince's legion under assault by a relentless wave of zombies.
This winter twist is ripped straight from Game of Thrones, where the phrase "Winter is coming" is a warning not only about a long, cold season, but also about the imminent approach of the Night King and his seemingly endless legions of White Walkers.
It's something Jon Snow's coalition has tried, unsuccessfully, to prevent, but alas, the Night King succeeds and finally manages to bring his followers to the Seven Kingdoms, which coincides with the arrival of winter. Kingdom follows suit, albeit with Cho acting as a living, human Night King, ushering the undead through the freezing landscape. And with this rabid horde ready to feast on everyone, the crown prince, much like Jon Snow, is now viewed as his people's only hope.
Season 1 of Kingdom is streaming now on Netflix.