The cases taken by two remarkable Spanish judges against Gen Pinochet have progressed further than most people imagined possible, with the general's arrest on their warrants in London last Friday. But they still face stiff opposition from senior Spanish legal figures, and any support they get from the centre-right government of the Prime Minister, Mr Jose Maria Aznar, is likely to be reluctant.
The prospect of prosecuting a former dictator, in a country which has chosen to avert its eyes from the human rights violations committed by Gen Franco's regime, opens up an "appalling vista" for many Spanish conservatives. This was a point which the Chilean Prime Minister, Mr Eduardo Frei, was quick to make at the weekend. The Spanish transition from dictatorship to democracy in the 1970s was a model for ending military rule in Chile and Argentina in the late 1980s.
A Pinochet trial in Madrid would also increase the already volatile tensions created by the recent jailing of top Socialist politicians for participation in the 1980s "dirty war" against ETA. More than one Spanish general currently awaits trial on similar charges.
Judge Baltasar Garzon and Judge Manuel Garcia-Castellon are two of the so-called "star judges" at the Audiencia Nacional, which specialises in investigating corruption, drugs and terrorism. Judge Garzon is one of the most controversial - and most photographed - figures in Spanish public life. His gelled hair and intense gaze is a familiar image on the front pages of newspapers and magazines.
He has prosecuted many leading members of ETA, and was responsible for shutting down a radical Basque newspaper this summer. He has taken major cases against drug barons, some would say with more theatrical flair than legal finesse. But he has been equally zealous in pursuit of state terrorism, and has regularly come into sharp conflict with government and his judicial superiors.
He has been the bete noire of Mr Felipe Gonzalez's Socialist Party since 1988, when he began investigations which have now established that Socialist leaders were complicit with kidnapping, torture and murder. He became even more controversial when he flabbergasted the public by briefly becoming a member of a "reforming" Socialist administration in the 1990s. He left abruptly when, he says, he discovered the reform programme was an electoral gimmick. He returned to the bench to prosecute his former colleagues.
Critics say his zeal is based on disappointed ambition, when Mr Gonzalez did not offer him a ministry. Admirers see him as a cool, clean crusader in a sea of corruption.
The two judges have co-operated to develop an imaginative and ambitious legal strategy against international human rights violations. They were both approached in 1996 by relatives of Spaniards who "disappeared" or were tortured in Chile and Argentina, and took the cases which have led to Gen Pinochet's arrest.
However, their efforts have been strongly resisted by the legal establishment. A chief prosecutor at the Audiencia Nacional argued in December last year not only that Spain had no jurisdiction in such cases, but that the Chilean and Argentinian military had seized power "in order to maintain public peace". There was a public outcry, but he received the full support of Mr Aznar's attorney general, Mr Jesus Cardenal. The two judges have had to use all their legal resources to proceed with the cases.
Mr Aznar is in an awkward position here. He is personally close to the Prime Ministers of both Chile and Argentina, and Spain has big economic interests in both countries. Many members and supporters of his conservative Partido Popular are former Francoists, with a nostalgic affection for Latin American dictators.
But Mr Aznar has been the scourge of the Spanish Socialists for their dirty war activities. How could he demand prosecution for relatively small-scale death squads at home, and support Gen Pinochet's immunity for much greater crimes?