To clear a debt that isn't his, Han Seong-eun enters a high-stakes contract marriage with Cha Jinwook, a blind billionaire and dominant alpha. The rules are humiliating: Seong-eun must undergo a nightly "physical inspection" to prove his fidelity, yet sex is strictly forbidden outside of their cycles. With a pregnancy clause looming and his husband remaining ice-cold, Seong-eun is trapped in a stalemate. That is, until his brother-in-law, Cha Jinhyeong, moves in. Jinhyeong is bold, dangerous, and more than willing to "help" Seong-eun fulfill his marital duties. In a house full of secrets, Seong-eun is about to learn that playing the brothers against each other is a very dangerous game.