This is seriously one of the most intense, thrilling,engaging, nail biting dramas of all time!! for thriller, mystery and detective lovers it's a must watch!! It has the right amount of suspense,thrill and scare. I might as well say that this is the best thriller kdrama I've watched so far.
And it's so unpredictable and leaves you hanging at the end of each episode! Like literally every episode is a cliffhanger making you crave for more.
Edit : they ended it pretty well. The chemistry between the characters was amazing! I almost wish for another season but most likely there won't be any..