‎ Kilala si Martina bilang nerd at mahinhin na sa tingin ng karamihan at hindi makabasag pinggan, But behind Martina’s shy and nerdy appearance hides her terrifying true self. Every night, she becomes an assassin who is greatly feared in the underground society, known by the name “Rose Venom.” Kinakailangan ni Martina gumawa ng ilegal na gawain para sa pagpapagamot ng kanyang lola dahil hindi sapat ang kinikita niya sa pagiging waitress. ‎‎Samantalang ang loyal customers ng coffee shop nila na gwapo, mayaman, magaspang ang ugali, matapobre na si Itzael ay pinagpaplanuhan kung paano niya makukuha ang loob ng waitress na si Martina. Not because Itzael liked her or had feelings for her, but he wanted Martina to be his wife and the mother of his children because he was annoyed that his dad kept telling him to get married and have kids, since he was the only one still single among the three siblings.  ‎‎Kalaunan ay pumayag na si Martina sa offer ni Itzael dahil nasilaw siya sa yaman at kaya niyang gawin sa oras na pumayag siya sa offer. She agreed not because of the young CEO’s money or wealth, but because of her mother’s death case that had long been forgotten and whose culprit was still unknown. Martina didn’t think that the moment she agreed, her heart might end up broken because of the rule Itzael made — that no feelings should develop between them.‎‎Will Martina be able to stop her feelings, or will she end up falling even more for the man she knows only wants her body and not her heart? Or will she choose to harden her heart and continue being a secret assassin just to forget the feelings slowly growing inside her for Itzael?‎‎‎