Lonsdale was put under intensive surveillance. He had an office in Wardour Street, and a flat in the White House, near Regent's Park. Both were bugged, and visual observation posts established nearby. To all intents and purposes, he lived the life of a London playboy, traveling abroad frequently and pursuing a succession of glamorous girls attracted by his easy money and good looks.
Houghton and Gee next visited London at the beginning of August, and again met Lonsdale, this time in a cafe near the Old Vic theater. The Watchers monitored them closely, even slipping into a table next to them. Lonsdale told Houghton and Gee that there would be no meeting in September, as he was visiting the USA on business, but that he was confident he would return in time to meet them on the first Sunday in October. If he did not appear, someone else they knew would come in his place.
On August 27 Lonsdale was followed from his flat on the sixth floor of the White House to the Midland Bank in Great Portland Street, where he deposited a suitcase and a brown paper parcel. Shortly after, he disappeared. The DG approached the Chairman of the Midland Bank, and obtained permission to open Lonsdale's safety deposit box. On the evening of Monday, September 5, the suitcase and package were removed from the bank and taken over to the MI5 laboratory at St. Paul's. The contents were spread out on a trestle table and carefully examined by Hugh Winterborn and me. After years of trying, we had stumbled across the real thing - the complete toolbag of the professional spy. There were a Minox and a Praktina, specialist miniature cameras for document copying. The Minox contained an exposed film, which we developed and recopied before replacing in the camera. The photographs seemed innocuous enough: snaps of Lonsdale and a smiling woman taken in a city which, after considerable analysis, we concluded was probably Prague. There was also a book on how to learn typewriting, which I knew at once must be connected with secret writing. By shining a narrow beam of horizontal light along the edges of each page, I picked out the minute indentations, where Lonsdale had used the pages as a carbon for his invisible secret messages. The typewriting book was sent down to Dr. Frank Morgan at AWRE, and became invaluable in boosting his research program into new methods of detecting secret writing.
The most interesting object was a Ronson cigarette lighter set in a wooden bowl. We X-rayed the lighter using Morgan's method, which showed the base to be hollow, containing several small items. They were removed with a rubber suction cup and tweezers, and were found to be two sets of miniature one-time code pads, one of which was clearly in current use. There was also a list of map references on a folded piece of paper, based on the London map book used by our Watchers.
Ever since RAFTER began, I had studied everything I could find about Soviet clandestine radio communications, and as soon as I saw Lonsdale's cipher pads, I could identify them as Soviet issue. This was no Polish intelligence officer - this was a full-blown KGB operation. With Lonsdale in radio communication with Moscow, we knew that if we could copy his pads and trace his signals, we would be able to decrypt them as they came in. Unfortunately, there were in Lonsdale's suitcase no signal plans giving a schedule of when and at what frequency to listen to his broadcasts among the thousands of messages which were pouring out every week from Moscow. RAFTER gave us the vital breakthrough. We decided to set up in the flat next door to Lonsdale in the White House, and by using active RAFTER, we would be able to tell when and at what frequency he was listening to his receiver.
Copying the code pads without arousing Lonsdale's suspicions was much more difficult. Without access to each sheet of the pads we would be unable to decipher his traffic. I knew from the Radiations Operations Committee that the Swiss intelligence service had recently found an abandoned KGB one-time pad, so I arranged for MI6 to ask the Swiss if they would be prepared to allow us to borrow it. They agreed, and I drove out to London Airport to meet the RAF plane which flew it over specially for us. The Swiss pad was very similar to Lonsdale's; each edge was covered with a thin film of glue to hold the pages together. We took it apart, and analyzed the glue. It was non-Western, but the Post Office technicians were confident they could make some up.
We went into the bank again on the evening of Saturday, September 17, removed the suitcase, and took it to St. Paul's. The pads were delicately taken apart and each page individually photographed. Then the originals were placed in a specially made jig, which held them tightly together so we could recoat the edges with our newly made-up glue solution. In the early hours of Sunday morning, we took the suitcase back to the bank, and waited for Lonsdale to return.
A few days later, I received a call from Tony Sale. He sounded distinctly agitated.
"There's something you ought to see. Some of the LIONSBEARD recording..."
LIONSBEARD was the code name given to the continuous RAFTER operation on the Russian Embassy. I took a taxi to Kensington Park Gardens, and ducked into our safe house on the next street. Tony Sale met me in the hall, and handed over a sheet of the LIONSBEARD needle printout.
"Any idea what that is?" he asked, pointing to two sudden bursts of receiver activity inside the Embassy in September.
"What dates are these?"
"Seems to be September 6, which was a Tuesday, and the other one is last Sunday - that's the 18th," he replied.
"Good God," I gasped, "they're the dates of the bank operations!"
Watchers had been used lightly during both operations to remove Lonsdale's suitcase from the bank. With a mixture of panic and despair, I took the printouts back to Leconfield House, and tabulated the exact times the Russian receiver was operating against A4's records of Watcher operations. The LIONSBEARD readings matched the A4 records perfectly. The Russians must have guessed we were onto Lonsdale.
I called for all the LIONSBEARD records, going back two and a half years, and laboriously checked through them all to see if there were other examples where the Russians had used their receivers in the middle of a Saturday or a Monday night. There was not a single occasion, other than these two, where the Russians listened between the hours of midnight to 5 A.M.
I took the material to Furnival Jones, and we went straight up to Hollis' office. He took the news calmly, and agreed the evidence of a leak looked strong. He instructed Furnival Jones to begin another urgent investigation into the Watcher service, and in view of the fact that Lonsdale was almost certainly a KGB illegal, transferred control of the case from D2 (Czechs and Poles) to Arthur Martin in D1 (Soviet Counterespionage).
On the face of it, Lonsdale's departure abroad provided the best test as to whether our suspicions were well founded. We all agreed that if he stayed away, it would prove he knew we were onto him. If he came back, it would indicate we were in the clear. Lonsdale had told Houghton he would try to get back for their meeting on October 1. Tension began to rise inside Leconfield House, as Furnival Jones' Watcher investigations once more drew a blank. Houghton traveled to London, but no one turned up to meet him. Even Furnival Jones seemed visibly shaken as the days ticked by without any sign of Lonsdale. Then, on October 17, our observation post opposite Lonsdale's office in Wardour Street identified him entering the building. The doubt and suspicion, which had been growing in intensity, melted away as we threw our energies into the hunt.