"Fix the WiFi," they said. "It'll be easy," they said. Jungwon should've known better. One glitchy connection. One hidden server. One file that was never meant to be found. And suddenly-he's staring at a murder that was supposed to stay buried. Kim Chaewon's case was closed. Forgotten. Filed away as a tragic accident. But the truth? It's alive. Watching. Waiting. And now... it knows him. With strangers closing in and danger crawling through every shadow, Jungwon runs to the last person he ever wanted to see again-his ex. Jay. Infuriating. Reckless. Still heartbreakingly familiar. Also, the one man who might keep him alive. But Jay has rules. No secrets. No lies. No running away this time. Too bad Jungwon's been running his whole life. Now they're forced to work together, chasing a truth that gets darker with every step... and a killer who might be closer than either of them is ready to admit. Because some cases don't stay cold. Some love doesn't stay buried. And some mistakes? They come back to kill you. A romcom-thriller where the tension is deadly, the banter is dangerous, and falling for your ex again might be the riskiest move of all.

Jay, a cold and ruthless CEO, has built his life around discipline and control. His world revolves around work and his son, Taesan-a quiet, withdrawn child suffering from severe social anxiety. Despite Jay's efforts, no therapist has been able to break through Taesan's walls. But everything changes when Taesan accidentally bumps into Jungwon, a young and vibrant child psychologist. Unlike with anyone else, Taesan doesn't shy away from Jungwon's touch, nor does he hesitate to respond to him. Jay's father, witnessing this rare interaction, sees an opportunity-one that Jay initially refuses to accept. Forced by his father's ultimatum, Jay finds himself trapped in an unexpected deal: a contract marriage with Jungwon. His only goal? To help Taesan recover and reintegrate into the world. But as Jungwon's warmth seeps into their cold home, lines start to blur. Taesan isn't the only one changing-Jay, too, finds his heart softening, drawn to the man he was never supposed to fall for. But can love bloom in a marriage built on a contract? And when the deal is over, will Jungwon stay, or will he walk away with the heart he never intended to steal?