As the people of France cast their votes today in the first ballot of a two-round presidential election, they not only will pick who runs their nation but may also decide the very future of the European Union.
Yet despite such big stakes, seldom has the outcome of a French election been as unpredictable; the entire race resembles a cliffhanger movie in slow motion, one in which it's not very clear who will be eliminated, in what sequence or for what purpose.
France's two-round presidential electoral system was designed to ensure political stability. Almost anyone can stand for office but, as no candidate ever gets over half of the votes required to be elected outright in the first round, the two front runners go into a second, and decisive ballot held a fortnight later.
By having the prospect of two consecutive ballots, the system allows people to pick their favoured contender in the first round and, having done so, vote in the second round - if their favoured contender does not make the cut - for someone who'd block their least favourite presidential candidate. As the old French saying goes: "In the first round, one votes with one's heart, while in the second, one chooses with one's brain."
The system also ensures that only contestants with a nationwide organisation stand a chance.
Seldom has the outcome of a French election been as unpredictable; the entire race resembles a cliffhanger movie in slow motion, one in which it's not very clear who will get eliminated, in what sequence or for what purpose.
Historically, that meant one candidate for the mainstream centre-right now called the Republicans, and one centre-left contestant representing the Socialists.
Not this time, however, for opinion polls indicate that neither the Republicans' nor the Socialists' candidates have galvanised the electorate.
The standard bearer for the Republicans is Mr Francois Fillon, a 62-year-old former prime minister who lives in an ancient castle, appears more at ease talking about his exquisitely tailored suits than national unemployment rates, and is dogged by allegations about the financial affairs of his British-born wife.
Meanwhile, the Socialists have 49-year-old Benoit Hamon, a man with little government experience but plenty of unusual ideas, such as legalising cannabis and promising to pay everyone a fixed salary regardless of whether or not they work. He bombed, and is predicted to get not more than 8 per cent of the votes.
Instead, the candidates with a better chance of reaching the final in this marathon belong to anti-establishment movements.
One of them is Ms Marine Le Pen, the leader of the far-right, anti-immigrant National Front; the other is Mr Emmanuel Macron, a former banker who is running as an independent, and presents himself as a left- and right-wing candidate at the same time.
But the real sensation has been Mr Jean-Luc Melenchon, a far-left charismatic agitator who proposes to tax "the rich" at a rate of 100 per cent of their income and shorten France's working week, which is already among the shortest in Europe.
All opinion polls indicate that Ms Le Pen will top today's ballots with around 22 per cent of the vote. The real question is who will follow her into the second round.
Until this weekend, that was predicted to be Mr Macron, credited by pollsters with the same level of political support enjoyed by Ms Le Pen.
Yet pollsters also warn that they may be underestimating Mr Melenchon's strength, for he attracts youngsters whose voting patterns are less predictable.
And all electoral surveys were conducted before the latest terrorist attack on Paris' Champs Elysees, the French capital's famous avenue.
That grim episode may work in favour of the mainstream Republicans' Mr Fillon, the only candidate with serious government experience.
He is already claiming that "France is at war" and could well pip Mr Macron to the second position in the ballot.
Either way, with an unprecedented quarter of the electorate still undecided, every surprise is possible as votes are counted tonight.
What is already clear, however, is that at least two-thirds of the electorate will be voting today for people who until recently were considered fringe candidates, a situation not encountered in France since the current Constitution came into effect more than half a century ago.
Furthermore, although all pollsters suggest that Ms Le Pen will be defeated in the second round by anyone standing against her, that can't be taken for granted either, as her National Front supporters are far more committed and likely to vote.
Thus the turnout will be decisive in the second ballot, scheduled for May 7.
And were Ms Le Pen to win, that would spell the end of the EU as it stands now, given that she has pledged to destroy the institution.
All other European governments hope the worst won't happen.
French politicians - including President Francois Hollande and his entire Cabinet - are in no better position. They will all be out of office in a matter of weeks, and are already impotent to influence their nation's future course.