"Some promises are too powerful to break... even by death." Heeseung lives a quiet life, surrounded by silence, shadows, and a secret he refuses to let go of. Once, his world was filled with warmth, laughter, and love but now, all that's left is the echo of a name and a presence he can't let fade. One night, the lights in his lab flicker. Something stirs. And suddenly... he's not alone anymore. But what happens when the heart remembers what the mind refuses to accept? Top: sunghoon Bottom: heeseung Are you ready? A love story wrapped in mystery, science, and longing. Because some souls never truly say goodbye.All Rights Reserved