It wasn't the staring eyes, nor the way he picked up an apple in front of me and cut it open with such careful deliberation. It was the vice-like handshake, the steely grip that made my fingers hurt. "Imad Mougnieh," he said, as if to show he wasn't on the run, wasn't afraid to use his real name.
Yes, he said, he was a "member of Islamic Jihad" - I knew very well he was the leader of the organisation, that he had arranged the kidnapping of so many Western hostages in Beirut - but he was in Tehran, in the upper floor of a luxury hotel. Safe from his enemies - but then again, that's probably what he thought when he climbed into his car in Damascus on Tuesday night.
Mougnieh was an enemy of America, an enemy of Israel; the latter's denial of responsibility for the car bomb that killed him will be seen by his supporters as a mere linguistic sleight of hand, and he knew the risks. His brother was assassinated in Beirut by a bomb meant for him and his own loathing for the CIA station chief in Beirut, done to death by Islamic Jihad after his 1984 abduction, was proof enough of Mougnieh's war with the United States.
William Buckley of the CIA was kidnapped, Mougnieh told me, because he was controlling the then pro-American Lebanese government of President Amin Gemayel, whose army had been seizing thousands of Muslims, civilians and militiamen, some of whom were tortured to death.
I had gone to see Mougnieh to plead for the release of my close friend and colleague Terry Anderson, the Beirut bureau chief of the Associated Press, kidnapped in 1985 and subsequently held for almost seven years in sealed rooms and underground dungeons.
Mougnieh tried to reassure me. "Believe me, Mr Robert, we treat him better even than you treat yourself." I shuddered. I didn't believe that. I had heard this language before. How they respected the innocents they had so cruelly deprived of freedom, the very freedom they demanded for their own friends and supporters.
Maybe Mougnieh sensed that. When I asked about Terry - this was in October 1991, a month before he was released - Mougnieh cast those staring eyes upon me. They never left my face unless he wished to discuss a phrase or a sentence with his friends in the same room.
He prefaced his remarks with the opening words of the Koran - just as Islamic Jihad's hostage messages and videotapes did. This was the man who had taken Terry and who would have taken me had the occupants of the shark-like cars that haunted the Beirut Corniche grabbed hold of me. He was utterly uncompromising.
"Taking innocent people as hostages is wrong," he admitted to my astonishment. "It is an evil. But it is a choice and there is no other option. It is a reaction to a situation that has been imposed on us - if you want to ask about the existence of some innocent people among the hostages, then this question should not be posed to us alone, when Israel kidnapped and imprisoned 5,000 Lebanese civilians in the south of Lebanon in the Ansar camp."
Israel had indeed imprisoned those men at Ansar after its 1982 invasion. Amnesty International had condemned the conditions under which they were held. "Most of the people in Ansar were innocent," Mougnieh added - he did not define innocent - "and this is not even to mention the invasion itself and the killing of many people."
Mougnieh, Lebanese by birth, was a man of frightening self-confidence, of absolute self-belief, something he shared with Osama bin Laden and - let us speak frankly about this - with President George W Bush. Islamic Jihad, it was said, tortured its enemies. So does al-Qa'ida. And so, as we all now know, does Mr Bush's army.
Mougnieh - and again we should speak openly about this - was a valued, respected and senior figure in Iran's security apparatus. "Islamic Jihad" was a satellite of the Lebanese Hizbollah, the old un-reformed Hizbollah, whose leadership would now like to forget - even deny - its association with abductions. In that sense, Mougnieh was a man of the past, pensioned off in Damascus, safer for the Iranians there rather than cosseted in a Tehran hotel room.
But back in his days as an intelligence officer, he was a powerful man. Because of the suffering he had caused Terry, I should have hated him. But I did not hate him.
In the course of our conversation, he would become angry, stabbing his right fist in fury as he condemned America for its support for Israel and for shooting down an Iranian Airbus civilian airliner over the Gulf in 1988. I had seen this kind of fury before, at cemeteries and at mass graves. If he had allied himself with Iran, his passion was genuine.
I pleaded for Terry again. Could he not feel compassion for my friend? Again, his eyes never left me. "Of course, it would be very easy to find the answer to this question if you had been the mother or the wife of one of the hostages in Khiam [Israel's torture prison in southern Lebanon] or the mother or wife of Terry Anderson. My feelings towards the mental pain of Terry Anderson are the same as my feelings towards the Lebanese hostages in Khiam - or the mother or wife of Terry Anderson." Amnesty had also condemned the tortures at Khiam.
By now, Mougnieh was already playing that most famous role in all US soap operas: America's "number one enemy". The US would not have been weeping if Israel did kill Mougnieh yesterday. America wanted Mougnieh dead or alive - and for all the usual reasons.
Not least was his involvement in the hijacking of TWA flight 847 from Athens to Rome in June 1985. Mougnieh was one of the gunmen on board and demanded the release of 17 Islamic Jihad members imprisoned in Kuwait and 753 Lebanese Shia prisoners held in Israel.
After wandering around the Mediterranean, the aircraft - almost all the passengers were American - eventually came to rest in Beirut where an American, Robert Stetham, was viciously clubbed over the face and body before being shot in the head and thrown from the plane in front of the world's cameras.
I saw his body in the American University Hospital, grey-faced, hair tousled, lying next to a plump Palestinian woman who had just been shot in a gun battle between Shia militiamen and the PLO.
Shia Muslim Amal gunmen loyal to Nabih Berri - today, Lebanon's pro-Syrian Speaker of Parliament - stormed the aircraft, hustled the hijackers and most of the passengers into vehicles and sped off into Beirut's southern suburbs. All the passengers were released, but Mougnieh and his comrades were secreted off to Damascus - only to re-emerge in command of a hijacked Kuwaiti jet with similar demands and with an equally brutal assassination; that of a Kuwaiti fire brigade official at Nicosia airport.
Live by the sword, as they say, and you die by the sword.
Thus to the bomb attack in Damascus, not far from an Iranian school, close to a local Syrian intelligence office, explosives under Mougnieh's own car and a body dragged from the vehicle by policemen.