Revenge?

Yoon hee was the hired assassin, in order to kill her target Shim Su ryeon. She apparently need to work at Jakomo with a position of Marketing manager as her big boss told her to do, she was only waiting for his signal to finish her mission.

Su ryeon was the former CEO of Jakomo. While Logan was Su ryeon's dead husband, the policed accused logan that he kills himself and immediately closed his cased, but Su ryeon doesn't believe in what the polices said, and throw her own investigation about Logan's death to find his culprit.

Shim Su ryeon X Oh Yoon hee