It was called "House of Cards," a short film about a philandering man dismembered for his sins, but prosecutors say the seven-minute gorefest was actually Mark Twitchell's dress rehearsal for a murder.

Twitchell, 32, is on trial in Court of Queen's Bench in the death of B.C.'s Johnny Altinger on Oct. 10, 2008.

The prosecution says it will prove that a week after Twitchell and his buddies made "House of Cards" in a rented garage, he carried out the same scenario for real.

"Mark sent out a general email to people describing being interested in a short indie film based on a killer that finds cheating husbands online, clears out their bank accounts online and kills them," Scott Cooke, one of Twitchell's friends and movie-helpers, told court Tuesday.

The script, entered as an exhibit, is about a man named Roger. As the movie opens, he is finalizing a date online, then says goodbye to his wife and kids before he leaves for the rendezvous.

He never gets there.

Roger gets to the woman's front door only to get Tasered and clubbed into unconsciousness. He awakes in a windowless room where he is duct-taped to an iron chair and being lectured and threatened by a man in a hockey mask.

"Roger, you've chosen to cheat on your wife. You chose to betray the mother of your children by attempting to sleep around with some slut you've never even met," says the character known only in the script as "Killer."

"That's going to cost you."

Under threat of death, Roger reveals his Internet pass codes. Killer then wipes clean the dating account used to lure Roger to his doom, then electronically empties his bank accounts.

He then takes a samurai sword down from a wall and tells the blubbering victim he will kill him after all.

No one will know, says Killer. "They'll just assume you ran off with one of your hussies.

"It's better this way," he adds. "Your wife won't have to live with a liar and a cheat for a husband."

And with that, according to the script, "the killer winds up and decapitates Roger in one smooth motion."

Cooke said that was changed during filming to a fatal thrust to a faux torso.

The script then reads: "(Killer) picks up a power saw and goes to town on dismembering the body off screen."

The plot twists at the end, when it's discovered the story is all in the mind of a writer, who is seen closing his laptop as the film fades to black.

Or is it in his mind?

Beside the writer are a hockey mask, gloves and stun gun. In the last line of the script, the writer tells his wife: "It's true when they say the best way to succeed is to write what you know."

Prosecutors suggest the ending is a metaphor. There are dizzying examples, they say, where fact and fantasy meet, mesh, blur and diverge.

Prosecutors say the key evidence is Twitchell's diary in which he details his crimes in grisly detail. The defence has signalled that it will argue the diary is nothing but a lurid work of fiction by the accused.

Prosecutors say there are parallels between Altinger and the fictional Roger. Both were lured to remote locations for online dates, though Altinger wasn't married.

There's no evidence his bank accounts were emptied, but his friends did get bizarre emails in the days after his disappearance which said he'd run off to Costa Rica with a woman named Jen.

Jen, or Jenny, is the name of Roger's wife in the script.

Roger, when he leaves on his date, tells his wife he's going to the gym. Twitchell's wife told court that on the night Altinger was killed her husband phoned her to say he was at the gym.

Prosecutors have shown exhibits of knives, saws, cleavers and blades in Twitchell's possession. They are stained, they say, with Altinger's blood. Altinger's remains were found dumped down a sewer, and appear to have been carved up like Roger.

Friends and family say Twitchell was fascinated by Dexter Morgan, a fictional character in books and TV who -- like Killer in "House of Cards" -- works by day for a police department but moonlights as a vigilante serial killer.

Twitchell's Killer metes out rough justice to unfaithful men. Judge Terry Clackson has told jurors they will hear evidence that Twitchell himself had been cheating on his wife. The couple, now divorced, has a young daughter.

Court heard Tuesday that within a week of Altinger's disappearance, police had Twitchell in their sights and were bringing his film buddies in for questioning.

That prompted him to send out an email. Introduced into evidence Tuesday, the missive warns his friends that while he can't say what is going on, he implores them not to talk to detectives.

"I've been screwed around with and don't appreciate it, so it's time to stop this and make them do their own jobs," he writes.

"You all have a right to silence and you should exercise that right."