On 12 January, 1938, M received a call from Olga Gray. Percy Glading had just told her that there was going to be another job, and it was taking place that weekend. Moscow Centre was getting greedy, he must have thought. It would have come as a surprise to M to learn that the NKVD knew even less about this operation than he did.
Glading had always wanted to prove the world wrong. In the past he had taken orders from his Soviet superiors – Borovoy, Maly and Deutsch – yet his abiding ‘aim and ambition’, he once told Olga, was to take over the ‘executive side of the work’ being done by the NKVD in Britain.1 To prove that he was up to the job, Glading had decided to carry out an espionage operation without first informing Moscow Centre. As before, he wanted Olga to be part of it.
M’s response was to step up surveillance on Glading’s home in Harrow, north London. Three days later this Soviet agent was seen leaving his house early in the afternoon, before he was lost by the MI5 watchers. He returned three hours later carrying a folded newspaper. It appeared to conceal a small book. The watchers could not be sure. The best way to find out was by making an arrest, yet this might be just another rehearsal using an ordinary book of no consequence, in which case an arrest would be a mistake. Glading was also alone, whereas Olga had said that a Moscow operative would be involved. It did not feel right. M decided to hold back.
The following morning Percy Glading left his house with the same carefully folded newspaper lodged under his arm. The MI5 watchers began their pursuit. This time they managed to follow him to Charing Cross Station, in central London, where he was seen heading towards the main public lavatory. He descended the steps, and at the bottom met a young man carrying an attaché case.
With one of the MI5 watchers just a few yards away, Glading handed over the newspaper and its contents to the man with the attaché case. This second individual was followed by the watchers to a residential address in Plumstead, which turned out to be his home. He was soon identified as Charles Munday, a twenty-two-year-old assistant chemist in the Woolwich Arsenal.
M now had the outline of a Soviet spy ring. Charles Munday, the chemist, and George Whomack, the middle-aged man involved in the first operation, both worked in the Woolwich Arsenal and were presumably responsible for getting stolen material out of the complex. Olga ran the safe house. Glading took photographs and supplied negatives to his Soviet controller, which were then passed on to Moscow. But if M ordered the arrest of Glading, Munday and Whomack now, the prosecution would rest on the strength of Olga’s evidence and the testimony of the MI5 watchers. It might be enough. It might not. M felt that he needed more.
Several days later, Olga received a call from Glading. He sounded tense. He said that he wanted to have lunch the next day. Without giving away anything specific on the phone, Glading intimated that a new job was in the offing and it could be bigger than the last. Olga agreed to the meeting, hung up and dialled M’s number.
The following day, Glading arrived at the Windsor Castle pub in Notting Hill, west London, carrying a suitcase. It contained his photographic equipment. He wanted to do another job, not the next week or tomorrow, but that very evening. This time Glading planned to take the photographs at Olga’s safe house. He told her to be back at the flat before six o’clock to help set up the camera. After that he would go to Charing Cross Station to pick up the stolen material.
At last, M decided to strike. He would collapse the house of cards that he had built up so meticulously around Olga over the past six years. He instructed Special Branch to make the arrests that evening.
At quarter past eight, Glading was greeted on the concourse of Charing Cross Station by a middle-aged man carrying a paper parcel. They walked together towards the exit while a team of plainclothes policemen closed in on them, an implosion in slow motion, and when the middle-aged man handed over the parcel the officers made the arrest. Percy Glading had flown too close to the sun. As he was led away by the police, he said nothing.
Back at the safe house, Olga was expecting to see Glading walk in the door; instead, her younger brother, Richard Gray, recently qualified as a policeman, bounded in. He told her to pack up her things and took her off to a hotel in East Horsley, Surrey, a different kind of safe house, where she would lie low until the trial.
Olga’s career as an undercover MI5 agent had entered its final phase. So much espionage work ends in a fog of uncertainty and irresolution. Olga’s penetration of the Communist underground was about to reach a sharp conclusion, one that would be played out before the world.