FAMILIAR characters are on stage at the Heritage Center in Bucks County: Scrooge, his nephew Fred, Bob Cratchit, Marley and, of course, Tiny Tim.

   But their behavior is strange. Fred and Bob are plotting a murder. Marley’s a drunkard. And Tiny Tim, instead of asking God to bless everyone, insults all with a big raspberry.

   And there you have the gist behind Joe Doyle’s The Christmas Carol Conspiracy: Scrooge’s Revenge, which is being presented by Actors’ NET of Bucks County, along with a new adaptation of A Christmas Carol itself, on alternating nights at the Heritage Center in Morrisville, Pa., Dec. 4 through 20.

   Two shows sharing about half a dozen main cast members — that’s the challenge Mr. Doyle and his wife, Cheryl, decided to take on this Christmas. And while the plays feature the same characters, they’re quite different.

   The Doyles first presented Scrooge’s Revenge during Actors’ NET’s first season in 1996, partly because they wanted to have fun with the holiday chestnut and partly because writing an original script saved money on royalty payments. The following year it went on to a run in Greenwich Village.

   Set one year after Scrooge’s life-altering Christmas Eve, Scrooge’s Revenge finds Fred and the Cratchits being blackmailed by Jacob Marley’s twin brother. It turns out it wasn’t ghosts who haunted Scrooge, but a scheme designed to scare the old skinflint into spreading the wealth.

   The plan worked, perhaps a bit too well. Marley’s brother has seen how well Fred and Bob are living and wants more money for wearing those chains and scaring Scrooge. Fred and Bob plot to kill the old man, while making sure Scrooge stays happy and merry.

   Then things start to get crazy.

   ”I wanted to say it was a hoax, and then during the course of writing it, I came up with plausible reasons, or ways of how he could have been hoaxed,” says Mr. Doyle, the managing director and resident playwright at Actors’ NET. “And it all kind of wrote itself. If you twist your mind enough, you just go in the right direction.”

   There have been requests from audiences members to revive the show, but just doing it alone wasn’t enough for the Doyles.

   ”I thought if we were to bring it back, I wanted to do something special,” Mr. Doyle says. “And since over the years we’ve done theme shows on alternate nights like the male and female versions of ‘The Odd Couple,’ it just dawned on me: Well let’s go for broke and see if we can do both the original version and do it straight — because we both love it as is — and then the sophomoric send-up of it.”

   The Doyles then started work on their adaptation of A Christmas Carol, one that is faithful to Dickens’ tale.

   ”We wouldn’t do ‘A Christmas Carol’ any other way,” says Ms. Doyle, Actors’ NET’s artistic director. “It’s practically a sacred text in our culture, and I think to mess with the real story would be almost sacrilege.” Indeed, much of Dickens’ language is in their script via a narrator and by working Dickens’ words into character dialogue.

   Furthermore, the Doyles (who collaborate on the staging and directing of A Christmas Carol while Mr. Doyle directs Scrooge’s Revenge) are focusing on the story itself and its themes: the true meaning of Christmas, society’s responsibility toward the poor and the emotions Scrooge faces. It’s a counter to big-budget versions of the tale, on stage and screen (Mr. Doyle nearly shudders as he mentions the trailer for the new 3-D version starring Jim Carrey).

   ”It shouldn’t be about how fancy the staging is or how fancy it looks but the emotional content of each piece of it,” Ms. Doyle says. “And we both work very hard as directors to make sure that’s where the focus is and where it stays. It’s not supposed to be about the other stuff, even if we could afford it.”

   Several actors will play their parts in both shows, including Jim Banar as Scrooge. For the classic version, Mr. Banar says he wants to play the character not as someone who is mean to the core, but as a man who has been beaten down by life. He says Alastair Sim’s portrayal in the 1951 film of A Christmas Carol (which he watches with his wife and son every Christmas Eve) is the standard, but he doesn’t want to imitate that legendary performance.

   ”He isn’t overtly angry — it’s just, ‘I don’t get it anymore,’” Mr. Banar says of Scrooge. “He (Sim) played that so well so the challenge for me... is to not mimic. You don’t want to do Alastair Sim because you can’t,” he says, adding the key to Scrooge’s Revenge is to play the character realistically, and let the humor grow from the situations. “The fun part is being able to play the same character in a totally ridiculous situation but play him as you would in the other play,” he says.

   Most audience members are sure to be familiar with the original Christmas Carol, but the story offers opportunities for real emotional depth, such as when Scrooge sees himself as a lonely child, or as a young man losing the love of his life.

   ”That’s the type of thing that will make any show that’s been done 100 times come through because you’re playing it real each time with the people you’re on stage with,” Mr. Banar says. “And that’s the key, along with good direction like we’ve had here, that’s what makes shows really good.”

A Christmas Carol will be performed at the Heritage Center, 635 N. Delmorr Ave., Morrisville, Pa., Dec. 4, 12, 18, 8 p.m., Dec. 6, 20, 2 p.m. The Christmas Carol Conspiracy: Scrooges’ Revenge will be performed Dec. 5, 11, 19, 8 p.m., Dec. 13, 19, 2 p.m. Tickets cost $20, $17 seniors, $10 ages 13 and under (separate admission is charged for each show); 215-295-3694; www.actorsnetbucks.org