Margaret Denise Quigley , professionally known as Maggie Q, is an American actress and model. She achieved international fame starring as the title role on The CW's action-thriller series Nikita that aired from 2010 to 2013. In 2014, she portrayed Tori Wu in the film adaptation of Veronica Roth's novel Divergent and its sequels, and stars in the Kevin Williamson CBS drama series Stalker as Lieutenant Beth Davis.