Episode list

If Hae Jun hadn't been curious, he wouldn't have stumbled upon a time machine. With a few button presses, he quickly figures out how to use it, and that marks the beginning of his journey as a time traveller. Yoon Young is occupied with her job as an editor for a renowned writer, leaving her little time to spend with her mother. Then, suddenly and unexpectedly, tragedy strikes as Yoon Young receives a call that her mother has been found dead.

Despite her confusion about the current situation, Yoon Young recognizes a small possibility of altering the future after a chance encounter with 19-year-old Soon Ae, prompting her to follow her closely. Soon afterwards, Yoon Young learns about the mistreatment that Soon Ae is facing from the other kids and also notices that some of the children resemble those she knew from the future.

Yoon Young was able to enter school thanks to Hae Jun's help. As soon as she began her classes, she realized that one of her classmates was the future Ko Mi Sook. However, she was unaware of the danger that Ko Mi Sook posed, as she was extremely clever. Hae Jun ensured that Yoon Young remained at school until he could pick her up, but when he returned, Yoon Young was nowhere to be found.

With the day drawing closer, Hae Jun experiences mounting anxiety over the possibility of failing to prevent the murder, given his limited information and unexpected developments. While the school is on a field trip, a new student teacher is introduced, whom Yoon Young finds strangely familiar. Later that night, while alone at home, Yoon Young recalls the true identity of the student teacher.

Now that Yoon Young has developed trust in Hae Jun, she believes it's crucial to disclose her relationship with Soon Ae and Hee Sub to him. With the missing pieces of the puzzle given to him, Hae Jun finally comprehends the reasons behind Yoon Young's fixation on Soon Ae. More importantly, Hae Jun proposes an alternative perspective on what could have occurred to Yoon Young's mother, leaving Yoon Young stunned at her own foolishness for losing hope.

Hae Jun feels it's unnecessary to share what he saw with Yoon Young, complicating the situation. He grows agitated as events deviate from his expectations. Meanwhile, Yoon Young is surprised by Soon Ae falling for Hee Sub despite her attempts to break them apart. Later, Yoon Young understands why Hae Jun hid things from her, and as she talks, something clicks in Hae Jun's mind.

Hae Jun and Yoon Young feel relieved, knowing that Lee Ju Young is out of harm's way. Immediately, their attention shifts toward preventing a second tragedy. They hold on to the belief that as long as they remain vigilant and closely monitor the potential victim, nothing untoward will occur. However, their decision to solely focus on a single target may have been an oversight, as unexpected events tend to unfold precisely when and where one least anticipates them.

Hae Jun and Yoon Young find themselves in a dire situation as the events they thought they had escaped become a reality before their eyes. Yoon Young, who had hoped to change the future for the better, is devastated by the gravity of her circumstances. Setting aside the past, they now seek their next steps.

The situation looks grim for Hee Sub and Yu Sub, but Hae Jun realizes the lengths to which Hee Sub is willing to go to safeguard his loved ones. Consumed by guilt over her sister's demise, Soon Ae takes it upon herself to aid Hee Sub in proving his innocence, but her father disagrees. Eventually, Yu Sub discovers that Hee Sub has been apprehended. Hae Jun devises a solution to free Hee Sub from trouble, while Yoon Young anxiously waits for him outside an inn.

Hae Jun and Yoon Young have gained a deep understanding of how a minor mistake can have devastating and irreversible consequences for others, particularly when it involves family matters. They now direct their attention to Hae Kyung, whom they fear might be the next target. Hae Jun empathizes with Hae Kyung's situation and endeavours to prevent her from fleeing her home. Meanwhile, a thought occurs to Hae Jun, sparking his curiosity to personally investigate something.

In Hae Jun's memories, there is a notable absence of shared moments with his mother. Nevertheless, his curiosity drives him to uncover the truth about his mother's character. Writing holds paramount significance in Soon Ae's life, but her hard work hangs in the balance as the threat of Mi Sook stealing it looms closer. Yoon Young refuses to allow her mother to endure the same life that awaits her if she gives everything up.

The case grows more perplexing and convoluted with every investigation conducted by Hae Jun and Yoon Young. In the midst of her own emotional turmoil following her sister's demise, Soon Ae's predominant worry revolves around her mother's well-being. On a calm evening, when everything appears serene, Hae Jun receives an urgent and terrified call from Bum Ryong.

Hae Jun is caught in a difficult situation when he is discovered at the scene of a murder, coincidentally at the wrong time. The key to proving his innocence lies in revealing his existence as a time traveller. By demonstrating his ability to foresee the future, Hae Jun successfully vindicates himself and gains allies who assist him in his search for the perpetrator. In the meantime, Hae Jun tries to maintain a facade of disinterest toward his mother but finds himself irresistibly drawn to Chung Ah.

Rather than idly waiting for the case to resolve itself or relying solely on the police, Hae Jun takes action by involving the media to expedite the investigation. The increased public attention creates unease among certain individuals, and Chung Ah is one of them. She unexpectedly opts to shut down her teahouse. As she prepares to leave the town, Chung Ah turns to Hae Jun and asks him to accompany her to the station, and the two share a little conversation.

After enduring a series of harrowing experiences, Hae Jun finds himself confronted by the culprit, whose identity leaves him utterly astounded. Remarkably meticulous, the culprit erased every possible piece of evidence before being caught. As Hae Jun starts to piece together the puzzle, the trials he faced begin to make sense. He meticulously follows the trail, step by step, in the hopes that it will lead him to the vital evidence he needs.

With everything seemingly restored, Hae Jun realizes he is unable to go back. Suspecting there must be a reason behind this, he embarks on a final set of visits to say goodbye to his close family and friends. Yoon Young follows a similar path, ensuring her loved ones are prepared for the unexpected future. However, during their last journey together, Hae Jun encounters a special someone whom he is unwilling to reveal to Yoon Young.