In Bogota, Colombia, Cataleya's father, Fabio, is having a meeting with Don Luis, a drug lord, to pay off his remaining debt and leave his employment. Fabio, however, knows that Don Luis will put a hit out on him for leaving with a valuable item that he holds and Don Luis wants. Fabio rushes home and warns Alicia, his wife, that Marcos, Don Luis's capo, is coming after them. While Alicia packs, Fabio hands Cataleya a business card, which should give her entry to the U.S. embassy, in case she finds herself alone. Fabio hands Catleya the item that Don Luis wants, telling her not to lose it and to give it to the Ambassador so that she can get a U.S. passport. He also gives Cataleya the address of her uncle in Chicago, who will take care of her. He tells her to "Never forget where you (she) came from." Marcos and his thugs arrive at Fabio's residence. Fabio, Alicia, and Cataleya try to escape, but the house is surrounded. Fabio and Alicia have Cataleya sit at the kitchen table and not move no matter what. Cataleya witnesses both her parents being gunned down.
Marcos locates Cataleya and tells her that he's a good man and he killed her father because he betrayed Don Luis. Marcos knows that Cataleya knows the whereabouts of the unknown item and says Don Luis will give her whatever she wants if she gets him what he wants. Cataleya stabs Marcos in the hand with a kitchen knife and escapes her house. She runs through the streets of Bogota, pursued by thugs from all directions, and is able to slip away by hiding inside a water sewer. She then uses the business card her father gave her and goes to the Ambassador's office. Cataleya vomits out onto the Ambassador's desk the valuable information Marcos was looking for, which she swallowed while she was sitting at the kitchen table in her house. In exchange for this, they give her a passport, and she takes the first flight to America. At the airport, Department of Social Services guides Cataleya. Cataleya pretends to want to use the bathroom and escapes to take a bus to her uncle, Emilio, in Chicago. The next day, Cataleya and Emilio talk about Cataleya's dreams. Cattleya had at first wanted to be a designer or artist, but, because of her parents' death, Cataleya presents a strange request to Emilio: she wants him to help her become a killer. Emilio says he will help her but looks disturbed and enrolls her in an expensive private school.
Cataleya berates Emilio for not taking her seriously and says if he won't teach her how to be a killer, she'll find someone else to. Emilio gives Cataleya a demonstration of how to be a killer by pulling out a gun and firing at the front wheel of a random passing car. Emilio tells Catleya that if she wants to be a killer, she has to be smart, psychological, and know her surroundings, otherwise, "(she'll) end up dead within 5 years". He makes her a deal. If she goes to school, he will teach her how to be an assassin.
Fifteen years later, Cataleya works for Emilio as a hitwoman. She knows how to get in and out without being detected, has amazing fighting skills, and is good with any weapon. She leads a quiet double life with an artist boyfriend who knows almost nothing about her. One night Cataleya, seemingly intoxicated, rams her car into a police car. The officers arrest and interrogate her. They find no name in the database, along with no I.D., no license, but a library card, with the name of Valerie Phillips. The police charge her with DUI and throw her in the precinct's jail for the night. Later on that night, Genarro Rizzo, a big time gangster, is being transferred to the jail. Cataleya pretends to be asleep and when the guards leave her section of the jail, she gets up and begins undressing, donning a black bodysuit, removing the wig she had on her hair. She uses the hairpin from inside her wig to unlock her cell door. Cataleya knocks out the guard and takes his weapon. She approaches Genarro, wakes him, kills him and draws an orchid (a cataleya) on his naked stomach. She leaves the drawing of the cataleya on her victims in hopes that doing so will attract the gangster that killed her parents.
The police, hearing the gunshots, quickly pull the alarm and start searching for Genarro's killer. Cataleya makes her way back to her cell by going inside the air vent with a detour outside over the edge of the roof. Cataleya makes her way back inside the jail, gets back inside her cell, redresses, and pretends to be asleep when the guards check on her. The unconscious guard comes to, and his gun is right next to him. Next day, police release Cataleya with a court date for the DWI. When Cataleya leaves she takes off her fake hands, which are identical to skin, and throws them away.
After further assassinations, the FBI decide to release the information regarding Cataleya's calling card is revealed to the public. It is then revealed that Don Luis has been relocated to the US by making a deal with the CIA. Don Luis sends Marco to hunt down this assassin. Marco eventually tracks down Emilio and kills Cataleya's remaining family.
Cataleya, wrought with grief breaks into an FBI agent's home and tries to explain her situation to him. After threatening to kill his family if he does not cooperate, she gets the address of Don Luis from a CIA agent revealed earlier to know where Don Luis has been relocated into.
Cataleya loads an armored van with guns and her two dogs and drives to Don Luis's estate for vengeance.
After a lengthy gunfight, Cataleya confronts Marcos in the bathroom. They engage in hand-to-hand combat where Cataleya uses plastic toothbrushes as stabbing weapons. A defeated and wounded Marcos picks up his pistol and points it to Cataleya who disassembles the gun and stabs Marcos with the gun barrel, killing him. She picks up Marcos's cellphone and leaves.
Don Luis, meanwhile, sneaks away from a hiding spot and gets in a large black van. He drives away when he receives a call from Marcos. Answering the call, he finds out Cataleya has killed Marcos. He threatens Cataleya and taunts that he is where she cannot find him, but he will regroup and find her. Cataleya calmly responds he is exactly where she wants him to be. It is revealed that Cataleya's two dogs are in the back of the van, and mauls Don Luis to death when Cataleya commands the dogs to "eat".
Her artist boyfriend is held for questioning, when he receives a phone call from Cataleya where they say their goodbyes and Cataleya is seen at a gas station somewhere, getting on a bus.