William H. Macy On David Mamet & ‘Speed-The-Plow, ‘House Of The Re-Animator,’ More…

“I’m terrified — the scariest thing I’ve ever done.” So begins a conversation these days with William H. Macy as he takes over Jeremy Piven’s role in the David Mamet play “Speed-the-Plow.”

After Piven dropped out in December because of mercury poisoning resulting from eating too much seafood, Macy was forced to jump right in and learn his lines in less than two weeks.

“I’ve had a rough three or four weeks,” Macy told MTV News. “I had to be off-book in ten days, which is crazy. Mamet said to me, ‘Bill, you’ll be okay. The script is more of a guideline than something you need to follow word for word.’ But every time someone told me I’d be great, it just killed me.”

If anyone was hoping the Oscar-nominated actor might take a shot at Piven and his much-ridiculed mercury mea culpa the way Mamet did (“My understanding is that he is leaving showbusiness to pursue a career as a thermometer,” the playwright told Variety), Macy won’t take the bait.

“Jeremy got sick,” he said, choosing his words very carefully. The two actors have not spoken since “Speed-the-Plow” was in previews last fall.

The drama on Broadway, though, is not the only adversity Macy’s facing at the moment. Financing for his directorial debut “Keep Coming Back” collapsed late last year in the wake of the economic meltdown. The film tells the story of a shy young man who joins an AA group so he can spend time with the love of his life, an alcoholic ex-stripper to be played by Milla Jovovich. Thankfully, Macy said, the entire cast has stayed committed.

“Milla is the bee’s knees. And Steve [Buscemi] produces and directs his own stuff, so he knows how these things go. Steve is going to play Satan. He hasn’t got any lines, but he’s funny as hell.” While Macy assembles fresh financing, he’s begun to narrow down his male lead prospects to about ten actors, though he declined to drop any names. If all goes according to plan, they’ll start shooting in the spring.

A film that won’t be shifting into production shortly is “House of the Re-Animator,” another in the series of cult-favorite horror flicks from Stuart Gordon.

“I spoke with Stuart three or four months ago,” said Macy. “I think there’s a script, but it’s not at a place where he’s showing it to anyone. I’m supposed to play the dead president” — one reportedly based on George W. Bush.

And don’t expect a big screen Macy/Mamet reunion soon. “Come Back to Sorrento,” which Mamet adapted with his wife Rebecca Pidgeon, is on the back burner as Mamet finishes another script. But Macy is hopeful the movie will eventually get off the ground.

“Mamet is prolific,” he says. “He goes to the bathroom and comes out with a novel.”

Clearly, though, the project weighing most heavily on Macy’s mind is “Speed-the-Plow.” Asked if he expected things to get easier, Macy laughed. “Are you kidding?” He laughed again. “No, I think I’ve gotten past it now. Last night I started to rock!”

If you were Macy, what would you say to Piven? And which of these Macy projects are you looking forward to the most?