They spent their last night alone in their Tehran home. She nursed a flu. He tended to faxes and phone calls in a sepia-toned study where aging veterans of Iran's struggle for democracy often sipped tea and debated politics.

In and out of prison over the last 40 years, Dariush Foruhar and his wife Parvaneh had fought the Shah, then worked briefly with leaders of the 1979 Islamic Revolution before its repressive side triumphed. A labor minister in the first revolutionary cabinet, he was later jailed by the ruling ayatollahs when he challenged them too.

Dariush, with his hint-of-a-handlebar mustache, and Parvaneh, who shed her mandatory head scarf whenever possible, always criticized Iran's lack of freedoms. But they were a couple whose lives were winding down in a trickle of homespun protest leaflets and small-time meetings.

Which is why their violent deaths so moved Iran in a way their lives of political action never did, dramatizing in a tragic way the nation's struggle to decide what type of society it is to become. Others have been killed too, and in a similar fashion. But the murders of Dariush and Parvaneh Foruhar last Nov. 22 have remained a symbol and a rallying cry, still vivid eight months after the crime.

When pro-democracy students took to the streets of Tehran in recent days, the catalyst was the closing of a liberal newspaper. The broader frustration, however, was with a system that, despite a clear majority's desire for more openness, and despite President Mohammed Khatemi's reform efforts, proved capable of attacking protesting students in their dormitory--just as it had proved capable of targeting marginal figures like the Foruhars in a series of killings that pro-Khatemi forces continue to investigate.

As the protests grew and turned violent, for instance, the killings came back to haunt security forces yet again. Students marching through the street shouted Foruhar's name and suggested his killers are still hiding behind clerical robes.

On that last night in their home, Parvaneh called her sister, a conversation the sister remembers as gloomily terse: "I'm sick," she said. "I'm going to bed." Dariush spoke briefly with a doctor and transacted some business.

Late the next afternoon, a handful of colleagues gathered for the weekly meeting of the Iranian National Party, a gray-haired group clinging to a movement born nearly 50 years ago under prime minister Mohammed Mossadegh. Down a narrow alley, they stopped near the Foruhars' gated walkway and rang the bell.

No answer.

Someone scaled the courtyard wall and opened the gate. Mohammed Ibrahim Holeghri, an elder of the bunch and a lifelong friend, strode to the front door. It was unlocked. He looked to his right and saw that the door to Foruhar's study was slightly ajar. He pushed and felt a heavy weight against the other side.

Squeezing through the narrow opening, he found his friend propped in a wooden chair, neatly dressed in the gray suit and collarless Nehru shirt preferred by Mossadegh in the 1950s. A dozen stab wounds surrounded his heart.

Holeghri phoned a colleague, then left the room and called for Parvaneh. She was in the bedroom, crumpled on the floor wearing bedclothes and a housecoat, her cheek slammed against the carpet, with similar wounds.

The visitors sobbed, and their thoughts converged.

"These," Holeghri said of the assassins, "were professional."

In an earlier era, news of the murders would have spread quietly through a local grapevine of dissidents and intellectuals, made more terrifying by the official silence.

However since his election, Khatemi has struggled to liberalize Iranian society in modest, incremental steps, fighting along the way against the country's conservative parliament, an influential coterie of wealthy Islamic charities and other forces skeptical of his plan to give civil institutions more power, extend the rule of law and open the economy.

Khatemi, himself a ranking cleric, says his aim is to sustain Iran as a religious society by modernizing it. But his first two years in office have been spent trying to consolidate authority against opponents who have impeached his allies and arrested his friends. As one Tehran diplomat put it, Iran really has no government now. Or perhaps it has several, each with its own domain.

In that climate, the seeds of a freer press were planted, and the murders of the Foruhars became front page news. They were still a hot topic during a visit to Tehran earlier this year. The funeral attracted thousands, transforming the couple's largely workaday lives into an emblem of people's desire to think and do what they want.

There are people in Iran who aggressively challenge the old order. There are religious scholars who would recast fundamental notions of the current system; there are clerics who vent against clerical rule; there is Khatemi himself, a man whose range of thought is heretically broad.

Some have been harassed, some jailed. But when it came to killing, the targets were second- and third-tier thinkers, like Foruhar. It is as if the killers purposefully aimed low, hoping to destabilize Khatemi's presidency without assassinating anyone with too high a profile.

What they did instead was trigger a debate in Iran's government that ended with appointment of a commission to investigate the killings. The group reported daily to the president, and, according to Khatemi's cabinet secretary, suspicion focused almost immediately on the government itself.

The possibility that members of Iran's Islamic government might resort to murder to undermine Khatemi "was not far from the mind," said cabinet secretary Mohammed Ali Abtahi.

On Jan. 6, the government disclosed what those who saw Foruhar's body had assumed: Agents of the state committed the killings. Subsequent reports indicated as many as 10 agents, officially termed "rogues," were involved. One, identified in the Iranian press as a deputy minister in the intelligence agency, committed suicide last month in prison, reportedly by drinking a hair-removing solution.

There still, however, is no guarantee that the full extent of the murder plot will be made public. It was in part demands in the press for more information that led authorities early this month to suppress publication of the left-leaning Salam newspaper, triggering the past week's Tehran University demonstrations. Friends of the Foruhars and relatives of other victims say they will not be satisfied until details are divulged in a public trial. They hope as well that a new interior minister will help Khatemi control an agency many Iranians feel is above the law--a sentiment echoed by the protesting students.

The fact that they even entertain such possibilities shows how Iran is changing; what happened to Mohammed Mokhtari shows how it remains the same.

Active in a small group hoping to form a freelance writers' guild, Mokhtari and his associates early in the fall were hauled before the country's Revolutionary Court.

As his son Siavash relayed the story, the judge told his father that while he might not be breaking the law, his activities threatened to cross the society's "red lines," and could prompt retribution by "groups that act instead of talk."

Late on the afternoon of Dec. 3, Mokhtari left his apartment on the fourth floor of a high-rise building, walked past the security guard, local art galleries and antique stores and down the tree-lined promenade of Vali Asr Street toward the market at Tajlis Square.

Somewhere along the way, according to police accounts relayed to the son, several men approached Mokhtari and took him away in a white, Iranian-made Paykan sedan.

That night the family called police and government officials, and Siavash made the first of several trips to the morgue. Sometimes a friend accompanied him, and a week later the friend was successful.

"They've killed Mokhtari too," the friend screamed when he found Siavash's father among the latest crop of unidentified corpses.

His body had been found at a cement factory on the outskirts of Tehran, a ring of bruises around his neck.

Had she known about the discovery of Mokhtari's body, Sima Pouyandeh said, she would not have let her husband leave for work. Mohammed Pouyandeh was also helping organize the writers' guild, and had likewise been rattled by the judge's warning and the Foruhar murder.

When Mokhtari disappeared, Pouyandeh's wife said her husband was "in a twilight zone . . . asking what was to be done," and worrying about his own life. The notion of murder and martyrdom in some ways seemed ludicrous. In a society with such large issues under debate, a man who translated Balzac into Persian could hardly appear threatening.

Sorbonne educated, he sustained himself, his wife and their 17-year-old daughter in a small apartment by translating United Nations documents on human rights and women's issues. On Wednesday, Dec. 9, they had their usual breakfast of rolls and coffee alone, because their daughter had left early for school and music practice. She is a violinist, partial to Bach.

Early in the afternoon, he phoned his wife to tell her he would be late because of a writers' guild meeting.

As he left his office at a downtown research foundation, witnesses later told his wife, three men in a white Paykan sedan presented credentials and forced him to accompany them.

That night, Sima Pouyandeh began the same grim search that Mokhtari's family had a week before.

"I just worried and I thought he must have been arrested. I called all the police stations and his office. Nobody knew anything. I was crying and begging them to do something to protect the life of my husband."

After three days she received word from authorities in nearby Shahriar who had found a corpse that fit her husband's description dumped by a railroad track. On a Sunday morning, she claimed the body. There was a gash on his forehead, and a ring around his neck she thinks was made by an electric cable.

CAPTION: Maryam Mokhtari attends the funeral in December of her slain dissident husband.

CAPTION: Arash and Parastou Foruhar grieve at the funeral of their father, killed in November.

CAPTION: Mourners carry the coffin of dissident Dariush Foruhar in November. The killers of Foruhar and his wife, said a friend, "were professional." The government says "rogue" agents of the state committed the crime.