Cardiothoracic surgeon Oh Yeon Joo's father mysteriously went missing while writing the last chapter of his webtoon "W". Yeon Joo goes to his office and is shocked to see a scene of a bloodied Kang Cheol, the main character of W, on her father's monitor. While reading something left behind by her father, a hand from the monitor pulled her in. She found herself on the rooftop of a building, next to a man lying down in blood. She manages to save him and realizes that the person she saved was Kang Cheol. She later discovers she can only enter and leave the webtoon depending on Kang Cheol's feelings.
- Other name: 더블유,W-두 개의 세계,W – Two Worlds Apart
- Genre: Action, Comedy, Drama, Fantasy, Melodrama, Murder, Revenge, Romance, Serial Killer, Suspense, Thriller
- Status: Completed
- Duration: N/A min
- Country: South Korea
- Network: N/A
Cast: Ahn Se Ha, Cha Kwang Soo, Choi Min Yeong, Dong Yoon Seok, Han Hyo Joo, Heo Jeong Do, Hwang Seok Jeong, Hyeon Seung Min, Jeong Yoo Jin, Jin Hyeon Kwang, Kang Ki Yeong, Kang Pil Seon, Kim Eui Seong, Kim Jae Il, Kim Ji Eun, Kim Na Woon, Lee Chae Kyeong, Lee Jong Seok, Lee Se Rang, Lee Shi Eon, Lee Tae Hwan, Nam Gi Ae, Nam Jin Bok, Park Choong Seon, Park Geon Rak, Park Min Ha, Park Seong Taek, Park Won Sang, Ri Min, Ryoo Hye Rin, Seo Kwang Jae, Seo Shin Ae, Yang Hye Ji, Yeo Woon Bok