Flashing lights, swarming paparazzi, a mysterious Fiat Uno, a swiftly aborted proposal to assassinate a Balkan leader — what will jurors make of it all in reaching a judgment on the deaths of Princess Diana and her lover Dodi Fayed?

Testimony has ranged far and wide in an extraordinary coroner's inquest, without shedding much light on claims that they were victims of a plot directed by Prince Philip. The coroner, Lord Justice Scott Baker, is expected to begin his summation Monday, which may take several days before it goes to the jury.

The key question for the jurors is whether the car crash in a Paris road tunnel on Aug. 31, 1997, was an accident or something more sinister.

Mohamed Al Fayed has not budged from his belief that his son and the princess died at the hands of British security agents, acting at the prince's behest.

French police concluded that the couple died in an accident, caused in part by excessive speed and by the high blood-alcohol level of the driver, Henri Paul. A British police investigation reached the same conclusion.

More than 240 witnesses have given evidence since the inquest began on Oct. 2. Al Fayed's late bid to force the coroner to summon Prince Philip to testify, and for written questions to be put to Queen Elizabeth II, was summarily rejected by a higher court.

The inquest was in part an exploration of how the couple's speeding Mercedes came to slam into a concrete pillar, after apparently having a glancing collision with a white Fiat Uno; and in part an examination of Al Fayed's belief that he knew who drove the Uno, who employed him and why.

Diana's close friends, Prince Philip's private secretary, a former head of the Secret Intelligence Service and Diana's former butler, Paul Burrell, are among those who have been in the witness box.

There has been evidence that Diana feared dying in a car crash, but also had speculated about death in a helicopter or airplane crash; there was testimony that she feared Prince Philip, her former father-in-law.

The basic scene is familiar: the couple's car crashed as they were pursued from the Ritz Hotel by a pack of paparazzi photographers.

Some witnesses near the Alma tunnel said they saw flashes of light in the instant before the crash, other witnesses didn't notice any. Al Fayed's claim is that flashing lights disoriented the driver and sent the couple's car skidding into a crash.

But there was precious little evidence to back up Al Fayed's claims that his son and Diana were engaged, that she was pregnant and that Philip was at the head of a murder plot.

As the inquest progressed, some distance opened between Fayed and the lawyers working for him.

Michael Mansfield, Al Fayed's main advocate, steered away from accusing Philip or of claiming that MI6 assassinated the couple. He did suggest that rogue agents might have been involved.

"Mr. Al Fayed ... has certain beliefs which he has made clear. He is plainly not a member of MI6 or, certainly, the establishment either," Mansfield told the coroner on Feb. 20.

"He has certain beliefs and I have never at any stage withdrawn any of his beliefs but you will see I have focused very carefully on elements of what he is suggesting that may be true; in other words, for which there is, forensically, evidence to support his beliefs."

Mansfield has suggested that Diana's campaign against land mines was the motive for the conspiracy, and that elements of the government and the arms industry were frightened that Diana was assembling a dossier about land mines; a dossier, he said, that was "capable of exposing historically British involvement in Angola because of who manufactured the weaponry, how it was got in there."

Al Fayed believes the "establishment" simply didn't want Diana to marry his son.

When he testified on Feb. 18, Al Fayed affirmed his belief that the conspirators included Prince Philip; Prince Charles; former Prime Minister Tony Blair; Diana's sister, Sarah McCorquodale; her brother-in-law Robert Fellowes; two former chiefs of London police; driver Henri Paul; the U.S. Central Intelligence Agency; Diana's attorney, the late Lord Mishcon; two French toxicologists; Britain's ambassador to France; members of the French medical service; and three bodyguards he once employed.

Al Fayed has claimed that Diana's brother-in-law, Fellowes, was in Paris on the night of the crash sending messages to agents back in Britain. But none of Al Fayed's lawyers put that allegation to Fellowes when he testified.

Al Fayed was the only witness to claim that he knew that Diana was engaged to marry Dodi Fayed. He was told of the engagement, Al Fayed said, in a telephone call hours before the crash.

Likewise, Al Fayed was the only witness to definitely assert that Diana was pregnant. The pathologist who examined her body said he saw no evidence, her former lover Hasnat Khan said Diana was conscientious about taking her birth control pills, and staff aboard Al Fayed's yacht, Jonikal, said they found opened contraceptive packages in her cabin.

Former MI6 agent Richard Tomlinson, who disclosed that a colleague had once proposed assassinating a Serb leader, has also claimed that flashing lights were part of the plan. When he testified, however, Tomlinson acknowledged that he was wrong in claiming the proposal was aimed at former Serbian President Slobodan Milosevic, and probably wrong about the lights too.

Richard Dearlove, a former head of MI6, testified that the assassination proposal was swiftly dismissed.

Al Fayed said he had been thwarted in attempts to prove his theory.

"How can you want me to get the proof?" Al Fayed said. "I am facing a steel wall of the security service, Official Secrets Act."

The coroner asked Al Fayed if he could possibly be wrong.

"No way, 100 percent," Al Fayed said. "I am certain. I am the father who lost his son. And I know exactly the situations. I know exactly the facts."