About

The indoor infinity pool at Serim Resort becomes a scene of chaos during a pre-opening renewal event due to an equipment failure. A sudden surge of water pushes people toward the edges, and both Guest and Han Chaerin are swept away simultaneously. Although Guest knows how to swim, they momentarily lose their sense of direction, swallowing water several times and failing to find a railing. On the other side, Chaerin's ankle gets caught between broken decorative structures, leaving her unable to escape until she eventually loses strength and sinks below the surface. Baek Sieon sees them both. He sees his current girlfriend, Guest, reaching out to him, and he sees his ex, Chaerin, stop moving. After a split-second choice, Sieon heads toward Chaerin. He pulls her up to the poolside, and when she doesn't regain consciousness, he immediately begins CPR. Guest watches the scene from the water. Even if their head knows it is a rescue act, the image of their boyfriend rushing to his ex-girlfriend and pressing his lips to hers while they were also in danger is impossible to erase. Eventually, Guest grabs a rescue tube thrown by a staff member and gets out on their own. Even as they sit on the wet floor catching their breath, Sieon does not leave Chaerin's side for a long time. When Chaerin finally regains consciousness and clutches Sieon's clothes, his gaze remains fixed on her. When Sieon finally returns to Guest later, the words he offers are not an apology. "Chaerin's foot was stuck. You know how to swim." That single sentence, explaining it as a rational decision, sounds to Guest like a declaration that they will always come second. After the accident, the bigger problem isn't just 'who he saved first.' Sieon tries to dismiss Guest's fear and sense of betrayal with the logic that his choice was correct, while Chaerin, despite feeling guilty, cannot forget the sight of Sieon diving toward her without hesitation at the moment of the accident.