'Intruders' makes immortality a conspiracy

The stars of Intruders are starting to feel more like "intriguers."

The eight-episode BBC America series (Saturday, 10 p.m. ET/PT) is chock full of secrets and mysteries, from Mira Sorvino playing two versions of the same character to James Frain's ruthless assassin becoming someone else entirely later in the run.

And that's just the stuff they can talk about, which isn't much at all.

"All these characters are intertwined. We can't tell you how, but there's so much to come," Sorvino says.

The conceit of Intruders, written and executive-produced by Glen Morgan and based on Michael Marshall Smith's 2007 novel, is that a secret society called the Qui Revertiis devoted to finding immortality among its members by inhabiting the bodies of others.

Jack Whelan (John Simm) left behind his violent past as an L.A. cop and now lives in Washington state with wife Amy (Sorvino). An old high school friend (Tory Kittles) shows up out of nowhere, seeking Jack's help with a murder case, but Jack's life gets spun around when he discovers Amy has disappeared and finds strange text messages on her phone.

Whelan is the guy who leads viewers "by the hand into this crazy supernatural scary thing," Simms says. "Everything happens around him, and you find out as he finds out, and hopefully share his sense of incredulity and horror."

Morgan has been throwing audiences for a loop for more than 20 years — his resume includes The X-Files, Millennium, The Others, The River and the Final Destination movie series.

What was different about Intruders was its mix of horror and detective genres and its exploration of reincarnation, an interest Morgan's father passed on to him.

"Michael managed to take that topic and find a very adult, very smart, paranoid atmospheric thriller," Morgan says.

But only the first four episodes, directed by Eduardo Sanchez (The Blair Witch Project), stay close to the book — the last four veer off and were a pleasant surprise for the cast, Sorvino says.

Sanchez found certain aspects of the early scripts "frustratingly mysterious," but he says Morgan has created an array of enigmatic parts that keep you hooked. "If you're asked to explain what exactly is going on, you can't. But you are entertained."

Frain's Richard Shepherd is a shady killer "just wasting fools left and right" in the first episode. Who he's aligned with is anyone's guess at first, but early on "you see the first inkling of a human being behind this monstrous presence," he says. "How he relates to the other characters is quite profound."

It's Sorvino, though, who must be the most secretive because of the twists involving Amy later in the series. "The range of the role is really extraordinary — it goes from vulnerable broken-wing bird to Machiavellian and passionate and full of hubris," she says.

Sorvino feels there's a relevant theme in Intruders with the idea of "the one percent...the power elite of the world that controls and knows things none of the rest of us know. That could be a very real reality, even though in our story it has supernatural proportions."

She also was interested in showing different sides of characters, and for Morgan it's a metaphor for anyone having another soul or person inside of them.

"When you're having a fight with your significant other and you go, 'Who's this? It's an intruder.' Or when you look in the mirror and you go, 'Why did I say that? Oh, it had to be an intruder,' " Morgan says.

"And to be able to talk about eternity and eternal love and what happens when you go, that topic never strays from interest."