Arisa, a lethal and emotionless assassin, is given a high-stakes mission: kill Dr. Ethan, a brilliant young scientist developing an antidote for bio-weapons that could shift the global power balance. To carry out her mission, she poses as his lab assistant, infiltrating his life, studying his every move. But as she spends more time with him, Arisa starts feeling something she's never felt before—hesitation, curiosity, and, worse, affection. She becomes torn between her duty and her growing emotional conflict, especially as she uncovers pieces of a darker truth: Ethan isn't just a scientist. He's unknowingly being manipulated by a shadowy organization that has plans far more sinister than she imagined.