By JOE DESCHAMPS --

Here's a case for The X-Files:

Brad Merritt, bassist for Canadian rock group 54-40, is usually a talkative sort -- but ask him about the significance of the UFO that hovers above the quartet on the cover of its latest CD, Trusted By Millions, and he clams up.

"I don't know," he mutters when asked about the curious CD jacket. Then he pauses. And pauses.

Finally he breaks the uncomfortable silence.

"It's topical, campy, happenin' and funny. It shows we've got a sense of humor. That's not really coming across in this interview, though."

True enough. Then again, the veteran Vancouver foursome -- playing the MacEwan Hall Ballroom Thursday and Friday -- have addressed some sombre themes over the course of its seven-album, 16-year history.

Trusted By Millions is no exception.

Stick With Milly -- a powerful song about abortion -- features some of 54-40's most controversial lyrics.

"When Neil (Osborne, vocalist/guitarist) first wrote the song, he wasn't going to state an opinion. But I lobbied to say: `Which side of this thing are we on?'" recalls Merritt.

"People who believe we have the right to choose an abortion seem less likely to get out and state their opinion -- we're like a silent majority."

Yet the album's first single, Love You All, is possibly one of the band's most frivolous, lightweight tunes. If it sounds like a made-to-order single, Merritt reveals that's because it is.

"(We released) Love You All to sell records ... to give the listener or potential buyer an idea of where we are."

Which is still making passionate, thoughtful, aggressive rock 'n' roll.

"We're still vital," says Merritt.

"We're still writing interesting pop music that holds my attention. I look forward to every new album."