Blake Lively may be a pro at transforming herself into different roles, but her character in The Rhythm Section , Stephanie, is not. At least, not enough to convince Sterling K. Brown in this exclusive clip from the upcoming thriller. When Stephanie's family dies in a plane crash, it sends her life into disarray. It's only when she's informed that the explosion that killed her family wasn't an accident that her real story begins. She's hellbent on revenge and gets in over her head, wearing many disguises while she does it. However, she's not some heavily-trained CIA operative. She's just a woman, and in the new clip, she finds herself totally caught in a lie.