From the moment she set foot on a strange continent, Seo-Ah wasn't given a moment to rest. With a single "key" in her hand, her life is thrown into endless pursuit and threats. And the man who desperately desires that key is Oscar Reichinhardt. Notorious for his coldness and cruelty, the man was wary of Seo-Ah from the start, but at some point, his gaze begins to subtly change. A relationship where they must use each other to survive. However, as time passes while they are together, hatred and obsession transform into an inexplicable attraction.

A dangerous contract, an uncomfortable cohabitation. Political conspiracies that could explode at any moment, and forbidden feelings slowly spreading. The shadow of another person casts over the two, shaking their hearts even more.

Questions deepen as they approach the hidden truth, and an inescapable, fatal allure. At the end where hatred and love, atonement and betrayal are intertwined, who will truly survive?