For Tatiana Maslany, it's an embarrassment of riches.
As the star of the new BBC America series Orphan Black, the Canadian actress plays not one, not two, but three pivotal roles in the debut episode alone.
In the follow-up episode, add two more to Maslany's ever-growing list of characters.
"It's the greatest challenge I've ever faced as an actor," she says.
As such, Maslany should never be allowed to complain that there aren't enough interesting parts available for her. By the time this sci-fi/techno thriller wraps up its 10-episode first season, Maslany will have filled the screen with multiple versions of the same woman.
Suffice it to say that the ever-deepening conspiracy at the center of Orphan Black, which premieres at 8 p.m. Saturday, involves cloning.
Meet Sarah, a street-smart, English-born orphan living in North America. She has had a hard life and has made a lot of bad decisions, which include shacking up with an abusive drug dealer and abandoning her young daughter. But she wants to turn over a new leaf.
Sarah is alone at the railway station one evening when she witnesses a woman throwing herself in front of a train. Eerily, the woman looks like she could be Sarah's long-lost twin.
That's when Sarah cooks up a colossally bad idea.
She assumes the dead woman's identity so she can clean out her bank account, an act she sees as a shortcut to financial freedom, the fresh start she had hoped for.
Instead, Sarah becomes trapped in the other woman's life -- she was a police detective named Beth -- and gets sucked into a mystery in which look-alikes and assailants are lurking behind every corner.
If Sarah hopes to survive the ordeal, she will have to find out the story behind all of these clones, why some of them now are being killed and how she fits into the overall picture.
If that's not challenge enough, she also will have to continually fool a lot of people who knew Beth well, including a boyfriend and her police-detective partner. It's a delicate tightrope act, but Sarah has always been something of a chameleon. So if anyone can pull it off, she can.
"Sarah's unlike any character I've seen on television," Maslany says. "She is written so vividly on the page, struggling to survive as best she can in a world that's never made room for her."
Orphan Black is the latest scripted series to be coupled with the durably popular Doctor Who as part of BBC America's Supernatural Saturday lineup. This particular combination is the network's best one-two punch since Torchwood, an anarchic Doctor Who spin-off, ended its run.
The season premiere of Doctor Who is also Saturday, at 7 p.m.
As for Orphan Black, it's going to take several episodes before the conspiracy starts to make sense. The word "clone," for example, isn't even uttered during the first two hours.
But that's part of what makes the series so intriguing. Unlike many conspiracy thrillers that are guilty of getting too messily complex in the very first hour, Orphan Black takes its time, delicately unfolding as it draws the main character, and viewers, deeper and deeper into the rabbit hole.
Every time Sarah comes up with an answer, she also uncovers more questions.
"The series is completely unpredictable, gripping, dark and hilarious," Maslany says. "The writers take huge risks, and that's what excites me so much about Orphan Black.
"It pushes boundaries, always with intelligence."