W: Two worlds is an exciting, fast-paced drama that will leave you constantly guessing on the edge of your seat. The storyline is extremely unique and the main leads did a fantastic job in playing their roles. The acting was powerful and I really felt for them in some of the scenes. Although there are a few clichés such as good vs evil, the plot is well written and pretty unpredictable. My only caveat is that some of the subplots in Oh Yeon-joo's world were not as interesting. Overall, this drama is a must-watch and most certainly among the best kdramas out there.