The grand narrative that has defined Polish politics almost since the fall of communism, cutting a deep fissure through the country's political life, has been violently punctuated with the crash of a Tupolev 154 jet in Russia.
By killing President Lech Kaczynski and a number of his political allies, including the heads of Poland's military and central bank, the crash is not only a national tragedy and an administrative crisis, but almost certainly the end of a colourful and tumultuous era in Polish politics.
At its high point in the middle of the 2000s, Mr. Kaczynski's conservative Law and Justice party was a dynastic force in Poland, with Mr. Kaczynski holding the presidency and his identical-twin brother Jaroslaw the prime ministership.
The two were household names in Poland, after having been child movie stars familiar to children during the communist years, and then founding members of the Solidarity anti-communist movement in the late 1970s and 1980s.
Their socially conservative, arch-nationalist politics divided them sharply against the more liberal, European-minded forces of the Civic Platform party of Donald Tusk, the current Prime Minister.
Both forces emerged from the anti-communist movements of the 1980s, which quickly split in disagreements over whether the answer to communism was a return to a distant past of national glory, religion and agrarianism as envisioned by Law and Justice or a Civic Platform's free-market economy and membership in the European Union.
That division evolved into a deeply entrenched rivalry whose future, in the wake of this plane-crash disaster, is unknown.
Mr. Kaczynski and his brother divided Poles deeply, embarrassing more elite and cosmopolitan urbanites with their outbursts against feminism, homosexuality, the European Union and Germany during a period when Poland was developing strong economic and social ties with the outside word.
Others rallied behind a politics based on nation, family and church - - a politics that, for a time in the last decade, proved very successful in foreign policy after the Kaczynskis forged a tight alliance with US president George W. Bush.
That alliance brought economic and trade benefits to Poland, including the planned staging of a major US antimissile base in Poland (a move that infuriated Moscow); it also involved Poland sending a large number of troops to Iraq and Afghanistan.
The defeat of Jaroslaw Kaczynski by Mr. Tusk (a former rival for the presidency) in the 2007 parliamentary elections ushered in a more divided age in Polish politics, with Law and Justice controlling some government departments, courts and military bodies and Civic Forum controlling others.
But Poland's dramatic economic resurgence during the past three years, during which Poland has been one of the few countries to escape the credit collapse without entering recession or having banks fall, has turned fortunes toward Mr. Tusk's camp.
In that light, Mr. Kaczynski's angry recalcitrance toward the European Union and his party's alliance with Xenophobic far-right parties in the European parliament has seemed counterproductive to a larger number of Poles, according to surveys.
Many analysts expected presidential elections this autumn to produce a victory for Civic Platform, and thus a collapse and crisis of identity for the nationalist conservative branch of the old anti-communist alliance, symbolized by the charismatic twins.
Today's disaster could precipitate that collapse even sooner - - or it could provoke a sympathetic return to support of a political dynasty that has thrived on visions of threats from outside. A plane crash in Russia, even if it was a thoroughly innocent event caused by a Polish leader's aging aircraft, may help resurrect just such visions.