Alexandra Chando Alexandra Chando

ABC Family's The Lying Game may be based on the book of the same name, but the similarities pretty much end there.

"People who have loved the book will still get the tone in the series, but it takes on a life of its own," executive producer Charles Pratt, Jr. (Melrose Place) tells "Everybody you see on this show is somehow tied into the mystery, which is probably our biggest departure."

In the book by Pretty Little Liars author Sara Shepard, Emma Becker learns she has a twin sister Sutton Mercer, but when she meets her, she finds out that she's dead, and the story's quest is Emma's search to find the killer. In the show's first episode, Sutton (Alexandra Chando, who also plays Emma) is very much alive, but departs shortly thereafter to locate the twins' birth parents, leaving Emma behind to cover up for her absence.

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Still, many of the characters will be familiar to fans of the book. Sutton's sister Laurel (Allie Gonino), best friends Char (Kristen Prout) and Mads (Alice Greczyn), nemesis Nisha (Sharon Pierre-Louis) and ally/romantic interest Ethan (Blair Redford) all make appearances. Andy Buckley and Helen Slater star as Mr. and Mrs. Mercer and Adrian Pasdar plays Mads' overbearing father Alec Ryback. Mads' runaway brother, Thayer, whose whereabouts are a big mystery in the book, will be portrayed by Christian Alexander.

Pratt shares insight into why and how the show will veer far from the books, what new characters will be popping up and what the new meaning of "the lying game" will be.

Why change the book:
Pratt says he wanted Sutton and Emma to on-screen together, so the decision was made to keep Sutton alive, "at least for the time being," he teases. "Following [Sutton's] adventure is very relatable in our minds for kids who are adopted — that eventual day when they go off in search of their biological parents."

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New faces:
As seen in the clip below, it doesn't take long before Ethan figures out that his secret girlfriend Sutton has been replaced by her twin. Although Ethan and Emma become close (he's the only one aware of her secret), Pratt wanted to give him a male figure he could talk to, hence a brother. "Tyler Christopher plays Dan the cop ... and seems to be connected to our District Attorney [Pasdar] from way in the past."

Pratt says the book was also lacking lots of hunky male characters necessary for a good teen soap. "Derek (Ben Elliott) is a laid back guy who's been in trouble with the law and gets involved in the story," Pratt says. "He becomes a love interest for Char, and she's in a very dangerous high-stakes love affair with a guy who shouldn't be falling in love with this rich girl, but he is." Laurel's sister also gets a b.f. "Randy Wayne plays Justin Miller, who comes in the third episode. You start to wonder about him because: Is he too good to be true? It's also very interesting to see him fit into the family and how it plays into sibling rivalry."

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Forbidden love:
What's a good drama without a student-teacher relationship? "Mads is going to have a major crush on her ballet instructor Eduardo [Rick Malambri]," Pratt explains. "Ultimately, Eduardo gets way involved in the big mystery without wanting to be, and he's in the wrong place at the wrong time with disastrous results."

The parents won't be shoved to the wayside:
Expect major screen time from the folks. "More and more, they are a part of the mystery," Pratt says. "All of them are involved, from puppetmasters to innocent victims being lied to and maybe an affair way in the past. You're not going to see flashbacks, but you'll see photographs of Helen Slater at the homecoming dance and Andy Buckley, Adrian Pasdar and others."

A new meaning to the lying game:
In the book, the "lying game" referred to a secret clique that Sutton and her friends created to pull pranks on their classmates, including those in the group. Emma soon wonders if one of the jokes led to Sutton's murder. In the series though, Pratt says the lying game takes a backseat. "It's brought up at different times, but as something they did in the past," he says. "The actual lying games don't really tie in [to the show] because they tied into the murder [in the book] that we're not doing. We kept the title ... because the switch that these two twins have done is one big lie and almost every relationship and every story is based on lies and truth issues."

The Lying Game premieres Monday at 9/8c on ABC Family.

Watch a clip from the premiere below: