Agent Kelly (2020) on Netflix

Plot summary

Kelly earns her living as a contract killer, a trained assassin and experimental chemist who works with poison. She has just turned fifty, and the trade has left her weary, though anger and cynicism keep her from walking away from paid killings. That changes when she learns what happened to Sam, the young charge she looked after, who was raped and murdered. Kelly breaks protocol and goes after one of the men responsible, leaving his body in the gang's warehouse for the others to find. The gang is a professional criminal organization, and its members now want revenge of their own. Her superior Ed phones, urging her to let his agency protect her, but she refuses and flees to Spain.