Spoilers ahead, I guess. Nothing you wouldn't learn by the end of episode 1.
I thought I was done with zombies, but put them in Korea in the 1500's (I'm guessing?), add political plots and really amazing hats, and I am all over it!
For real, the setup is basically a Shadowlands plot. The king of the Joseon dynasty in Korea falls ill with smallpox. He has an adult son, though I didn't catch if he was from the king's deceased wife or a royal consort. In any case, she's dead, and the king now has a pretty young wife (of the conniving Cho family! Boo, hiss!), heavy with child.
Apparently, if the king dies before the child is born, the crown prince will become the king. If he dies after the child is born, that child will be the king, with the queen as regent. The crown prince will be right out of the line of succession, and probably killed by the Cho, just to be sure.
Sure enough, the king dies before the child is born (before the show even starts, actually), but the dastardly Cho have a plan. Using the resurrection plant, the king is brought back to life as a flesh-craving monster!
Chaos, of course, ensues.
This show is much more zombie-apocalypse than I would go for, but that basic scenario just begs to be played out on a smaller scale.