NEW YORK (AP) – All comfortably familiar by cop-show standards, "Life on Mars" begins with NYPD Detective Sam Tyler nabbing a murder suspect, who then gets a grilling from him at the precinct house. He takes a phone call in the age-old squad room, which has lately been upgraded with computers and a splash of colour on the walls.

But about seven minutes into the episode, viewers are struck by something unexpected. Tyler, too: He's the victim of a hit-and-run – and, after coming to, he realises the city (including his squad room, now reverted to typewriters and a drab green paint job) dwells in the year 1973.

This is the premise for ABC's "Life on Mars", which, premiering at 11 p.m. Bermuda time tonight, has socked Tyler with numerous challenges. He must sift through varied nutty explanations for why he's here. He'd better brace himself to cross paths with his former self. He needs to figure out how to get home to 2008. And he has to keep plugging at his job, fighting '70s-vintage crime while stripped of many tools and techniques he took for granted in what he regards as "the present''.

"Life on Mars" is based on the BBC hit of the same name. But that's just the stepping-off point for this new adaptation, says its star, Jason O'Mara (who in 1973 marked his first birthday).

"In the British version, there were just three options for Sam's condition: Is he back in time? In a coma? Mad? But we've come up with more than 13."

Right now O'Mara is killing time between scenes on the set at Kaufman Astoria Studios, where a feeling of long-ago entrenchment is palpable to any observer. Here are desks heaped with handwritten evidence files; a cigarette machine in the stark coffee room; photos of the incumbent president, Richard Nixon; an overall grunge that seems to have begun its steady accretion during Hoover's presidency.

The Irish-born O'Mara (seen in "Grey's Anatomy" and "Men in Trees") is the lone remaining cast member from a scrapped "Life on Mars" pilot that had placed the action in Los Angeles, teaming him with co-stars including Colm Meaney, Lenny Clarke and Rachelle Lefevre.

"I got a phone call," O'Mara recalls. "They said, 'The good news is, we're gonna continue with you as part of the show. The bad news is, your castmates won't be joining you'. That was a little strange."

Did it leave him with survivor's guilt? "Yeah," says O'Mara, smiling wanly. "Lots."

"We chose to set the show, and shoot it, in New York instead," explains Andre Nemec, who took over with his producing partners Josh Appelbaum and Scott Rosenberg last summer. "That made us rethink some of the casting choices."

Among their new hires: Gretchen Mol, who plays Annie Norris, a smart, ambitious would-be cop so far marginalised in the Police Women's Bureau.

Even in her crisp uniform, Mol exudes the porcelain "It Girl" glow she displayed much less primly in the 2006 film "The Notorious Bettie Page''. She also looks deceptively delicate.

"That's the perception," Mol acknowledges. "And it's a nice thing to play against with the character: Annie is strong! If you're in that business you HAVE to be strong."

She adds with a knowing smile: "The business I'm in, too."

A bearded, shaggy Michael Imperioli plays tough-guy Detective Ray Carling.

"I was looking for a series in New York," says this inveterate Gothamite who co-starred on "The Sopranos" as Tony's thuggish nephew Christopher and had a short TV hitch as a detective on the Manhattan-based "Law & Order''.

"I like playing cops, and this is a different spin," he says. "And when they told me they were going after Harvey Keitel – that was a good sign."

The august Keitel plays two-fisted Lt. Gene Hunt, with whom the culture-clashing Tyler quickly comes to blows.

Rounding out the ensemble is Jonathan Murphy ("October Road") as rookie Detective Chris Skelton and Lisa Bonet as Maya Daniels, Tyler's fellow cop and sweetheart left behind, in harm's way, in 2008.

"The show's not really a time-travel show," says Nemec, speaking from Los Angeles. "At its core this is a 1973 police show, so, every week, there will be a close-ended case. Meanwhile, we deal with the fact that Sam is in 1973 and doesn't know why, as we drop clues to lead the audience to why this is happening – and other `clues' to lead you astray."

Whatever the final answer may be, it's different from the one cooked up for the BBC series, Nemec says.

"We wanted to put ourselves into a completely different world where you couldn't just go to Wikipedia to find out the underlying mythology. We have our own answer, a really solid answer to the whole megillah."

But you'll have to bide your time, as will O'Mara, who has no more idea than his viewers why he's planted in this 1970s squad room.

"I can only play the next thing Sam discovers, whether it be about a case or about his predicament," says O'Mara, and that's the way he likes it. "I'm discovering the truth as I go, when I open each script."