Orphan Black is about Sarah, an outsider and orphan whose life changes dramatically after witnessing the suicide of a woman, "Beth", who looks just like her. 
Sarah takes her identity, her boyfriend and her money. But instead of solving her problems, the street-smart chameleon is thrust headlong into a kaleidoscopic mystery. She makes the dizzying discovery that she and the dead woman are clones... but are they the only ones? 
Sarah quickly finds herself caught in the middle of a deadly conspiracy, racing to find answers