VANCOUVER - There's a scene in an episode of the sci-fi series "Battlestar Galactica" where several characters, faced with an opportunity to wipe out the humanoid robots that are determined to destroy them, are weighing the pros and cons of genocide.

The robots, called Cylons, had earlier tried to eradicate the humans and at one point occupied a planet where the last survivors had settled, forcing them into what resemble refugee camps.

And there's a moment, says University of British Columbia researcher C.W. Marshall, when genocide seems like a really good idea.

"These were characters that I knew arguing on both sides of it, and I've never been put into the position of going, 'Well, he has a point, it would be better if they just got rid of them all,"' says Marshall, who co-edited "Cylons in America," a recently released book examining the series.

"And then, instantly, I'm repulsed with myself," he says. "It was really just an interesting moment for me to know that I'm not immune to thinking such things. I can bring myself to a state where that is conceivable."

Marshall says the episode is an example of the array of contemporary issues the series tackles.

They range from terrorism to religious fundamentalism and life in post-9-11 America - connections that are explored in the 18 essays compiled in the new book "Cylons of America."

"Battlestar Galactica," the hugely popular remake of the late-1970s cult-favourite, is currently in its fourth and final season.

Filmed in Vancouver, the show follows a group of humans aboard a fleet of spaceships, led by the warship Battlestar Galactica, as they flee the Cylons and search for refuge on a distant human colony - Earth.

There are terrorists, insurgents and suicide attacks waged by humans and robots alike.

Elections are rigged, prisoners are tortured, and there are debates about abortion.

It's no coincidence, Marshall says, that many of the issues explored by the show mirror those facing modern-day North America.

"Though it is a science-fiction show and we've got guns and spaceships, I think the issues and characters that we're seeing are true issues and true characters," he says.

"You're not seeing that type of discussion arising on the 'Gilmore Girls."'

Tiffany Potter, who co-edited "Cylons in America" with Marshall, says because "Battlestar Galactica" is science fiction and rooted in fantasy, it can explore topics in ways that would be difficult for a series set in the contemporary United States.

"The problem with talking about that on CNN or Fox News is you immediately risk alienating a substantial part of your audience," says Potter.

"As soon as you translate that to outer space, it's not real. You're able to make it about a space president and a space election. When you remove that threat to people's own self-construction, then they can ask the hard questions."

For example, when the Cylons carry out a terrorism campaign against the humans, it's easy for viewers to denounce such acts as they would in the real world.

But when the humans find themselves occupied by the Cylons, an image not unlike the U.S. occupation of Iraq, they engage in the same tactics and the distinction between right and wrong is more blurred.

"Science fiction allows people sitting around their living rooms to have conversations about things that are normally not allowable in polite discourse," says Potter.

"After you watch 'Battlestar Galactica,' the show might invite you to have a conversation about reproductive technology, about genocide, about violence and sex, about fundamentalism, about race."