To the world, Hwang Hyunjin is a ruthless, unyielding CEO who commands every room he enters. To Felix, he is a shadow-a cold, distant husband who comes home late, speaks in brief sentences, and leaves an empty space in their bed. Their arranged marriage feels more like a beautifully gilded cage. Felix accepts the silence, living a quiet life tucked away in Hyunjin's massive mansion. But when a dangerous threat from Hyunjin's corporate empire spills over into their private life, the distant CEO changes overnight. Forced out of the shadows, Hyunjin steps between Felix and the danger, revealing a fiercely protective side Felix never knew existed.

Hyunjin and felix are living together for three months now. To anyone they looked like any other normal roommates but only they knew the truth, though it was still hidden from eachother. Because...they knew if they let the truth out then nothing will remain same; it will change everything which they will not be able to reverse ever. But nothing remains hidden forever! Truth eventually find it's own way to come out!?! What will happen when they no longer understand the boundaries? What will happen when everything begins to look like a puzzle which they are afraid to solve!! ??