Cheol-ho, who is already suspecting about Sang-hoon, Yeon-joo, and Kang Chul’s existences, sets out to the site of Sang-hoon’ death to investigate. There, he discovers a tablet in Sang-hoon’s car, but he does not know that it was a replica of Seong-moo’s original tablet whom Seong-moo drew under Sang-hoon’s command just before he was told to destroy the original.
Yeon-joo is brought to the hospital and is already dying. At the studio, Seong-moo returns to his original state and is grieved to realize that his tablet is destroyed and Yeon-joo is shot and has vanished from the hospital. Kang Chul arrives from the webtoon world and tells Seong-moo that he had brought Yeon-joo to his world in his attempt to revive her but Yeon-joo unfortunately dies. Seong-moo faints after hearing the news and is confined to the hospital. While at the hospital, the depressed Seong-moo attempts to commit suicide before Kang Chul prevents him and convinces him that he can still revive Yeon-joo using the replica of the tablet, which was already under Cheol-ho’s possession. Before going back to the webtoon world, he tells Soo-bong to stand by for his “SOS.”
Cheol-ho traps and tortures Kang Chul, interrogating him about the tablet. He lures Cheol-ho into bringing the tablet to the hospital. Just in time, Kang Chul gives his SOS to Soo-bong, returns to the real world and summons Cheol-ho. Soo-bong grabs the tablet from Cheol-ho, and Seong-moo draws Yeon-joo, restoring her life and bringing her back to the real world. While drawing, Seong-moo discovers that he is slowly disappearing due to him being the alter ego of the already dead Sang-hoon. Soon after, the last episode of W begins, instantaneously transporting Kang Chul, Yeon-joo, and Seong-moo back into the webtoon.
A year has already passed in the webtoon; Kang Chul is put in trial and is charged of murder and of other crimes. He meets Yeon-joo before the guards put him away. Just as he was about to face death penalty, a key appears on his handcuffs and he escapes. He deduces it was Seong-moo who freed him from prison using the replica of the tablet, and finds him in his hideout tied up by himself. He learns that, upon entry to the webtoon world, Seong-moo began suffering from a condition similar to a multiple personality disorder. He has been an escapee from a mental hospital, shifting erratically between his normal self to Sang-hoon’s murderous, tantrum-like personality. Seong-moo also revealed to Kang Chul that his essence will slowly disappear unless he does anything evil like Sang-hoon.
Kang Chul brings the already grieved Yeon-joo to Seong-moo’s hideout. Seong-moo secretly pleads to Kang Chul to leave him behind to die in the webtoon so that they can have their happy ending, to which Kang Chul strongly disagrees. As the police arrive to arrest Seong-moo and the furiously curious Cheol-ho kidnap Do-yoon, Kang Chul and Yeon-joo realize that to end the webtoon, Yeon-joo will lose either Seong-moo or Kang Chul.
In their efforts to end the webtoon’s story together, Yeon-joo draws and makes copies of a CCTV footage showing Cheol-ho torturing Kang Chul and escapes with Seong-moo to a motel. Kang Chul confronts Cheol-ho to save Do-yoon, but Cheol-ho shoots Kang Chul, interrogating him this time about the real and webtoon worlds. Kang Chul struggles with Cheol-ho and escapes by car, calling Yeon-joo for help at a bus station. Yeon-joo drives away to find Kang Chul just as one of Kang Chul’s bodyguard arrive to guard Seong-moo.
Meanwhile, Seong-moo, who overhears that Kang Chul was shot, asks be untied and, using the tablet, kills Cheol-ho and spreads the CCTV footage to the authorities. He makes a farewell letter addressed to Kang Chul, and he sets out to find Yeon-joo to see her for the last time, as his essence starts to fade.
Later, Yeon-joo arrives at Kang Chul’s location to pick him up. Unbeknownst to her, Seong-moo arrives, sees her attempting to cross the road towards Kang Chul, and whispers his farewell for her just before he completely vanishes. Yeon-joo was still in the middle of the road when Kang Chul faints due to his injury: the story of W formally ends, sending Yeon-joo back to the real world. Moments after the story’s ending, Do-yoon arrives to rescue Kang Chul. After his recovery, Kang Chul is imprisoned and reads Seong-moo’s letter which contains his request to make Yoon-joo happy. After three years, Kang Chul is then released from imprisonment.
Meanwhile, the readers and fans of W all wonder about the story’s sudden ending. Yeon-joo and Soo-bong try to find Seong-moo to no avail. A depressed Yeon-joo walks in the rain towards the bus station where he saw Kang Chul fainting. She collapses while staying in the same spot, just as she saw a figure approach her. Yeon-joo wakes up in a hospital to see Kang Chul lying with him. She finally accepts Seong-moo’s demise and hopes that her relationship with Kang Chul will last for a long time.
