Roger Hollis was never a popular figure in the office. He was a dour, uninspiring man with an off-putting authoritarian manner. I must confess I never liked him. But even those who were well disposed doubted his suitability for the top job. Hollis, like Cumming, had forged a close friendship with Dick White in the prewar days. For all his brilliance, Dick always had a tendency to surround himself with less able men. I often felt it was latent insecurity, perhaps wanting the contrast to throw his talents into sharper relief. But while Hollis was brighter by a good margin than Cumming, particularly in the bureaucratic arts, I doubt whether even Dick saw him as a man of vision and intellect.

Hollis believed that M15 should remain a small security support organization, collecting files, maintaining efficient vetting and protective security, without straying too far into areas like counterespionage, where active measures needed to be taken to get results, and where choices had to be confronted and mistakes could be made. I never heard Hollis express views on the broad policies he wanted MI5 to pursue, or ever consider adapting MI5 to meet the increasing tempo of the intelligence war. He was not a man to think in that kind of way. He had just one simple aim, which he doggedly pursued throughout his career. He wanted to ingratiate the Service, and himself, with Whitehall. And that meant ensuring there were no mistakes, even at the cost of having no successes.

After the ARCOS raid in London in 1928, where MI5 smashed a large part of the Russian espionage apparatus in a police raid, the Russians concluded that their legal residences, the embassies, consulates, and the like, were unsafe as centers for agent running. From then onward their agents were controlled by the "great illegals," men like Theodore Maly, Deutsch, "Otto," Richard Sorge, Alexander Rado, "Sonia," Leopold Trepper, the Piecks, the Poretskys, and Krivitsky. They were often not Russians at all, although they held Russian citizenship. They were Trotskyist Communists who believed in international Communism and the Comintern. They worked undercover, often at great personal risk, and traveled throughout the world in search of potential recruits. They were the best recruiters and controllers the Russian Intelligence Service ever had. They all knew each other, and between them they recruited and built high-grade spy rings like the "Ring of Five" in Britain, Sorge's rings in China and Japan, the Rote Drei in Switzerland, and the Rote Kapelle in German-occupied Europe - the finest espionage rings history has ever known, and which contributed enormously to Russian survival and success in World War II.

In 1938 Stalin purged all his great illegals. They were Trotskyists and non-Russians and he was convinced they were plotting against him, along with elements in the Red Army. One by one they were recalled to Moscow and murdered. Most went willingly, fully aware of the fate that awaited them, perhaps hoping that they could persuade the demented tyrant of the great services they had rendered him in the West. Some like Krivitsky, decided to defect, although even he was almost certainly eventually murdered by a Russian assassin in Washington in 1941.

Mention interrogations, and most people imagine grueling sessions under blazing lamps: men in shirt-sleeves wearing down a sleep-deprived suspect with aggressive questioning until finally he collapses sobbing on the floor, admitting the truth. The reality is much more prosaic. MI5 interrogations are orderly affairs, usually conducted between 9:30 A.M. and 5 P.M. with a break for lunch.

So why do so many spies confess? The secret is to achieve superiority over the man sitting across the table. This was the secret of Skardon's success as an interrogator. Although we mocked him years later for his willingness to clear suspects we subsequently learned to have been spies, he was genuinely feared by Blunt and other members of the Ring of Five. But his superiority in the interrogation room was not based on intellect or physique. Mainly, of course, it was the devastating briefs provided for him by Arthur Martin and Evelyn McBarnet which convinced men like Fuchs that Skardon knew them better than they knew themselves. It was not only the briefs that helped Skardon but also the skill of the eavesdroppers. In the Fuchs case, Skardon was convinced that he was innocent until they pointed out where Fuchs had lied. This information enabled Skardon to break him. But Skardon himself played an important role too. He epitomized, in his manner, the world of sensible English middle-class values - tea in the afternoon: and lace curtains - so much so that it was impossible for those he interrogated to ever see him as the embodiment of capitalist iniquity, and thus they were thrown off balance from the very start.

The MI5 technique is an imperfect system. But like trial by jury, it is the best yet devised. It has the virtue of enabling a man, if he has I nothing to hide, and has the resilience to bear the strain, to clear himself. But its disadvantage is that hidden blemishes on an innocent; man's record can often come to the surface during intensive investigation and render continued service impossible. It is a little like medieval justice: sometimes innocence can be proved only at the cost of a career.

Much has been written about Harold Wilson and MI5, some of it wildly inaccurate. But as far as I am concerned, the story started with the premature death of Hugh Gaitskell in 1963. Gaitskell was Wilson's predecessor as Leader of the Labour Party. I knew him personally and admired him greatly. I had met him and his family at the Blackwater Sailing Club, and I recall about a month before he died he told me that he was going to Russia.

After he died his doctor got in touch with MI5 and asked to see somebody from the Service. Arthur Martin, as the head of Russian Counterespionage, went to see him. The doctor explained that he was disturbed by the manner of Gaitskell's death. He said that Gaitskell had died of a disease called lupus disseminata, which attacks the body's organs. He said that it was rare in temperate climates and that there was no evidence that Gaitskell had been anywhere recently where he could have contracted the disease.

Arthur Martin suggested that I should go to Porton Down, the chemical and microbiological laboratory for the Ministry of Defense. I went to see the chief doctor in the chemical warfare laboratory. Dr. Ladell, and asked his advice. He said that nobody knew how one contracted lupus. There was some suspicion that it might be a form of fungus and he did hot have the foggiest idea how one would infect somebody with the disease. I came back and made my report in these terms.

The next development was that Golitsin told us quite independently that during the last few years of his service he had had some contacts with Department 13, which was known as the Department of Wet Affairs in the KGB. This department was responsible for organizing assassinations. He said that just before he left he knew that the KGB were planning a high-level political assassination in Europe in order to get their man into the top place. He did not know which country it was planned in but he pointed out that the chief of Department 13 was a man called General Rodin, who had been in Britain for many years and had just returned on promotion to take up the job, so he would have had good knowledge of the political scene in England.

Feelings had run high inside MI5 during 1968. There had been an effort to try to stir up trouble for Wilson then, largely because the Daily Mirror tycoon, Cecil King, who was a longtime agent of ours, made it clear that he would publish anything MI5 might care to leak in his direction. It was all part of Cecil King's "coup," which he was convinced would bring down the Labor Government and replace it with a coalition led by Lord Mountbatten.

I told F.J. (Martin Furnival Jones) in 1968 that feelings were running high, but he responded in a low-key manner.

"You can tell anyone who has ideas about leaking classified material that there will be nothing I can do to save them!"

He knew the message would get back.

But the approach in 1974 was altogether more serious. The plan was simple. In the run-up to the election which, given the level of instability in Parliament, must be due within a matter of months, MI5 would arrange for selective details of the intelligence about leading Labour Party figures, but especially Wilson, to be leaked to sympathetic pressmen. Using our contacts in the press and among union officials, word of the material contained in MI5 files and the fact that Wilson was considered a security risk would be passed around.

Soundings in the office had already been taken, and up to thirty officers had given their approval to the scheme. Facsimile copies of some files were to be made and distributed to overseas newspapers, and the matter was to be raised in Parliament for maximum effect. It was a carbon copy of the Zinoviev letter, which had done so much to destroy the first Ramsay MacDonald Government in 1928.

"We'll have him out," said one of them, "this time we'll have him out."

"But why do you need me?" I asked.

"Well, you don't like Wilson any more than we do... besides, you've got access to the latest files - the Gaitskell business, and all the rest of it."

"But they're kept in the DG's safe!"

"Yes, but you could copy them."

"I need some time to think," I pleaded. "I've got a lot to think about before I take a step like this. You'll have to give me a couple of days."

At first I was tempted. The devil makes work for idle hands, and I was playing out my time before retirement. A mad scheme like this was bound to tempt me. I felt an irresistible urge to lash out. The country seemed on the brink of catastrophe. Why not give it a little push? In any case, I carried the burden of so many secrets that lightening the load a little could only make things easier for me.

It was Victor who talked me out of it. "I don't like Wilson any more than you do," he told me, "but you'll end up getting chopped if you go in for this."

He was right. I had little more than a year to go. Why destroy everything in a moment of madness?

A few days later I told the leader of the group that I would not get the files.

"I'd like to help you," I told him, "but I can't risk it. I've only got half a pension as it is. I can't afford to lose it all."

Some of the operational people became quite aggressive. They kept saying it was the last chance to fix Wilson.

"Once you've retired," they said, "we'll never get the files!"

But my mind was made up, and even their taunts of cowardice could not shake me.