Heartbeat episode 10 revealed that Do Sik’s family has been cursed with a short lifespan, and the only solution to break the curse is to kill a half-vampire and half-human and drink blood from its heart. Do Sik has been keeping an eye on Woo Hyeol ever since he realized that he was a vampire. He is hoping that Woo Hyeol will lead him to a half-vampire. Meanwhile, Hae Won has been trying to win over Woo Hyeol, but he seems to be more attached to In Hae. Woo Hyeol believes that Hae Won is Hae Sun’s reincarnation, and that he is supposed to love her, but his heart is telling him something else. Hae is his solution to becoming a full human, but if she falls in love with him, things are going to get complicated, and Master Yang Nam has already noticed it.
How Does In Hae Confess To Woo Hyeol?
At the party at the guesthouse, Woo Hyeol dances with In Hae while Hae Won watches them jealously. She had planned to ask out Woo Hyeol, but seeing him dance with In Hae agitated her. She shows her anger by breaking the stack of glasses, which leads to an abrupt end to the party. Woo Hyeol and In Hae stop dancing, and In Hae follows Hae Won as she storms out of the party hall. Hae knows what Hae Won is thinking and tries to clear up the misunderstanding. However, Hae Won accuses In Hae of having feelings for Woo Hyeol. The party doesn’t go well for any of them, and more so for Woo Hyeol.
After Master Yang Nam watches everything happen, he urges Woo Hyeol to focus on becoming a human. Woo Hyeol never asked Yang Nam why he had been voluntarily helping him, but this time he got the answer to his question. Master Yang Nam invented the Hawthorn and silver arrows that later killed a lot of vampires, and Hae Sun was also a victim of the same. Yang Nam felt guilty seeing Woo Hyeol suffer from the loss of his lover, and that’s why he offered him help. Woo Hyeol gets furious after hearing it, but there’s nothing he can do about it now. Meanwhile, Do Sik and Hae Won argue over who is doing a better job at trying to win over their love interest, and for the first time, Do Sik agrees with Hae Won. He feels that he might lose In Hae to Woo Hyeol. Hae Won finds out from Do Sik that Woo Hyeol is a vampire, but she isn’t surprised as she already suspected that he wasn’t a normal human.
Out of insecurity and fear of losing In Hae, Do Sik tells her to stay away from Woo Hyeol because he is a vampire, but to his surprise, In Hae already knows, and her reaction upsets him. She defends Woo Hyeol and assures Do Sik that he is not a bad person. Woo Hyeol also meets Hae Won to talk about the incident and makes it clear to her that just because she looks like Hae Sun doesn’t mean she is her. Woo Hyeol feels that Hae Won is nothing like Hae Sun, and that he should stop linking them based on appearance. Hae Won is offended by it, and Woo Hyeol is upset with this realization. He feels lost. He has been searching for Hae Sun for a long time, but Hae Won has disappointed him. In Hae has been waiting for Woo Hyeol to return home and goes searching for him when he doesn’t even return at night.
Woo Hyeol, who has been wandering alone on the streets, cheers up as soon as In Hae calls for him but collapses right after. In Hae gets scared as she can’t take him to the hospital either, but thankfully, Woo Hyeol’s vampire friends spot them at the right time. In Hae tends to Woo Hyeol all night after his friends feed him blood to make him feel better. As soon as Woo Hyeol wakes up, In Hae hugs him worriedly and confesses that she has developed feelings for him. Woo Hyeol has been trying to avoid showing his feelings, but after hearing In Hae’s confession, he gives in. As the new romance begins on one side, Man Hwi, Woo Hyeol’s enemy, offers to find a half-vampire for Do Sik. Man Hwi only works for money, and as soon as he hears that Do Sik is looking for a half-vampire, he reveals his identity to him and makes him an offer.
What Does Man Hwi Reveal To Do Sik?
Woo Hyeol and In Hae are feeling giddy after their love confession the previous night. Woo Hyeol tells In Hae that he felt like his heart started beating when he saw her coming at him before collapsing. However, Hae is curious about what Woo Hyeol feels about Hae Won, and Woo Hyeol tells her the truth: she doesn’t feel like Hae Sun to him. He even confesses to In Hae that he feels more excited to see her than Hae Won. Their romance has just begun, but Woo Hyeol’s friends declare that they will live in the mansion to take care of him in case he collapses again. Though Woo Hyeol understands and appreciates his friends’ concern for him, he is not impressed with their timing.
Meanwhile, Do Sik has accepted Man Hwi’s offer, but he is still skeptical about him. He thinks that Man Hwi must be dangerous if he can reveal his identity without fear, and he doubts he can trust him. Do Sik’s secretary has been keeping an eye on Man Hwi, and on the other hand, Woo Hyeol’s vampire friend, Rose, also sees Man Hwi coming out of a house that looks shady to her. Man Hwi is indeed dangerous and still feeds on human blood. He has human captives in the shady house but has managed to keep them hidden until now.
Since Woo Hyeol’s friends started living at the mansion, Woo Hyeol and In Hae haven’t had a chance to spend time alone. However, an opportunity comes to them when their neighbor leaves his kid in their care. With the excuse of taking him to the amusement park, Woo Hyeol and In Hae go on a date. After spending a happy time on their first date, In Hae asks Woo Hyeol when he is going to become a full human. She tells Woo Hyeol that she is ready to give him her blood, which is full of love now. Woo Hyeol avoided bringing up the topic to not make In Hae uncomfortable, but she looks prepared for it now. She wants Woo Hyeol to decide on a date for his transformation into a full human, and she plans to throw a birthday party for him that day.
While they are planning a new life together, Man Hwi has revealed the big news to Do Sik. Man Hwi tells Do Sik that Woo Hyeol is the half-vampire he is looking for, but Do Sik won’t trust him unless he sees a certain scar on Woo Hyeol’s body. Heartbeat Episode 12 ends with Do Sik getting the answer to his question and discovering the scar on Woo Hyeol’s body. Do Sik and Woo Hyeol are arguing over In Hae when Woo Hyeol senses danger near In Hae, and the scar on his body glows. Seeing that scar, Do Sik confirms that Woo Hyeol is a half-vampire like he has been looking for, which puts Woo Hyeol in danger. However, Woo Hyeol has found a secret too, which makes Woo Hyeol reconsider his decision. Master Yang Nam reveals to him that In Hae has to die if he wants to become a human. Just a little blood from In Hae won’t help him, and he needs to suck every bit of her blood if he wants to become a human. Woo Hyeol’s life has suddenly become complicated and unpredictable. He can die at Do Sik’s hands, sacrifice In Hae to survive, or disappear until he dies slowly while suffering.