To a zydeco backbeat, Laureen Harper and John Baird wend their way through the packed lobby of Ottawa's National Gallery. The occasion is the Fur Ball, a fundraiser for the Ottawa Humane Society, of which the Prime Minister's wife is the honorary chair. In keeping with the Mardi Gras North theme, guests on this late March evening in 2007 have been handed Venetian-style masks. Harper, her hair swept up, attired in a long black skirt, embossed jacket and jewellery she boasts was a gift from her husband, is quickly thrust into the centre of a photographers' crush. Yet her radar is attuned to the fact her escort, the recently named minister of the environment, is about to fasten his mask over his face. She takes action. In a deliberate stage whisper, she teases him that being photographed behind a mask isn't the wisest signal for a politician to send.

The quick -- and shrewd -- rescue is typical of Harper, who since her arrival in the nation's capital five years ago has become one of the nation's most intriguing political spouses. She arrived Laureen Teskey, a folksy, motorcycle-riding Albertan refreshingly unstudied in Ottawa mores. She joked about the "mucky-mucks" and drank beer from the bottle. Post-2006 election, she's been retrofitted. Now she's Laureen Harper. A photographic essay of life at 24 Sussex Drive in the July Chatelaine could be postcards sent from 1956. Harper, who ran a thriving business after having her two children, appears to be channelling Donna Reed as played by Ellen Barkin. She revels in her role as stay-at-home mom to Ben, 11, and Rachel, 8, boasting that there's no nanny, she makes the kids' lunches and that the Harpers are just an "average Canadian family." Her only public cause -- fostering homeless cats for the Humane Society -- is similarly heartwarming and unassailable, though the recent addition of 11 kittens rescued after a fire at a Cornwall, Ont., animal shelter adds credence to 24 Sussex's new nickname, the Cat Palace.

Laureen Harper doesn't give formal interviews; the PMO quickly shuts down Maclean's request. "The story's about him," she likes to say. Yet the Stephen Harper story isn't complete without putting a lens on the missus. Rarely have two opposites attracted to such potent political effect. He's IQ; she's EQ. He's the policy wonk; she's the people person. Her ability to put people at ease, her extroverted nature and self-deprecating humour serve as a foil for her policy-obsessed, often-hostile-seeming husband whose social demeanour can mimic balsa wood.

Indeed, the Yamaha-riding former free spirit is an intractable part of Stephen Harper's political imagery. In photographs they are often seen holding hands, a united front. Earlier this year, she shed tears at a military graveyard in Barlin, France, her husband's consoling arm around her shoulder. Within Conservative circles, Laureen Harper is known as the Secret Weapon. Baird calls her "a great person and a great asset to our team." The Harper camp didn't use Teskey on the campaign trail in 2004, a mistake they corrected in 2005, says Harper strategist and University of Calgary political scientist Tom Flanagan. "We'd send her out to local riding headquarters and she'd say, 'My husband couldn't make it, but I'm here.' " Harper alludes to his wife when it serves his needs. When asked in a January 2006 CBC interview if he'd travelled much, Harper responded in the negative, then noted his wife had "made a pilgrimage" through Africa, referring to a six-month trek in the mid-'80s. "I get a much more accurate read on the realities of life in other parts of the world from Laureen," he said. In February, announcing the Canadian HIV Vaccine Initiative with the Bill and Melinda Gates Foundation, he quoted his wife's cheeky praise that Gates was the "sexiest man in the world."

In Canada, the Prime Minister's spouse has no official role; ceremonial duties are carried out by the Governor General. There's no "first lady" per se, though Laureen Harper is referred to by that title informally in the PMO. The women occupying the role have provided an odd and often unorthodox parade -- the backroom-operative Olive Diefenbaker, the caustic Maryon Pearson(who once quipped "Behind every successful man is a surprised woman"), the unprepared Margaret Trudeau, the militant Maureen McTeer, the polished Mila Mulroney, the reluctant Sheila Martin. Fairly or not, their identities have been grafted onto their husbands' political legacies. Even in an era of dual-career couples, the political spouse retains the power to glamorize, humanize, mobilize, scandalize, even strategize. As her role model, Laureen Harper has cited Aline Chrétien, one of the most guarded yet effective political spouses Ottawa has known. Low-key, rarely interviewed, Madame Chrétien was said to be her husband's most trusted adviser and the more ambitious of the two. Laureen Harper appears an even more complex creature. An activist in the early days of the Reform party, she ran a business so successful her husband enjoyed calling himself a "kept man." "The joke was that she subsidized the Reform party in the early days," says Ken Boessenkool, an economist and long-time Harper insider. She doesn't cleave to orthodoxies. Nor does she share her husband's religious convictions. "Stephen has a strong will everyone knows about," says Boessenkool. "But she has a very interesting will of her own. They're two strong wills living under the same roof which creates its own interesting dynamic. But when they go in, they go in as a team."