What will happen once human cloning becomes scientifically feasible?

That question is addressed with chilling logic in BBC America's superb sci-fi thriller Orphan Black, which returns for a second season Saturday at 9 p.m. And it ain't pretty.

Tatiana Maslany plays multiple roles as clones - we've met seven so far - created by a powerful conglomerate named Dyad and its scary head scientist, Aldous Leekie (Matt Frewer).

Set in Toronto, Orphan Black is told principally through the eyes of one of the clones, English-born grifter and single mother Sarah Manning.

The story opened last season as a fascinating mystery. At loose ends for money, Sarah one day witnesses an identical-looking woman, police detective Beth Childs, commit suicide. Intending only to empty her bank accounts, Sarah grabs Beth's wallet and keys and assumes her identity. She soon finds herself enmeshed in a deadly conspiracy.

Beth had discovered she was one of more than a half dozen clones, human beings owned by Dyad - the company holds the patent on their DNA. Sarah also learns that Dyad has kept tabs on the clones since birth by inserting its agents into their lives to become their husbands, lovers, and friends.

Maslany is riveting as the different clones, each with her own look, her own idiosyncracies, quirks, and speech patterns.

There's Alison Hendrix, an uptight, pill-popping suburban housewife and amateur actress; Cosima Niehaus, a brilliant if whacked-out genius scientist; Helena, a crazed serial killer; and the scariest clone of them all, Rachel Duncan, the heartless executive who runs Dyad's Toronto offices.

As if Dyad weren't bad enough, we find out in the second-season opener that a group of religious fundamentalists has decreed that the women are less than human and deserve to be killed.

Orphan Black, like all great works of science fiction, provides us with an imaginative exploration of how scientific advances alter our world, how new tech raises moral questions and affects every facet of our social, political, and economic life.

Brilliantly written and photographed, it's as thrilling, exciting and groundbreaking as The X-Files was in its era.


Orphan Black

9 p.m. Saturday on BBC America.