Sarah (Tatiana Maslany) is a woman with problems. Shes on the run from her abusive boyfriend, from whom shes stolen cocaine she hopes to sell and finance a new life for her and her young daughter, whom she abandoned months ago at the home of a foster mother. But Sarah didnt count on bumping into Beth on a train station platform. Beth looks just like Sarah -- or, she did, before she stepped into the path of an oncoming train. Sarah impulsively decides to take on Beths identity, using her keys to visit Beths apartment and her ID to extract Beths money from the bank. But Beths identity comes with strings: Shes a cop who shot a civilian, and shes under police investigation and being chased by mysterious, murderous strangers. Oh, and Beth also has some mysterious connection with a bunch of women born right around Sarahs birthday who, despite living in different towns, all share the same face. Does Sarah have a twin? Or is she just one of an army of clones? Its up to Sarah and her sidekick, foster brother Felix (Jordan Gavaris) to find out what kind of mystery theyre up to their necks in.