Professor Paul Broda was introduced by Tam Dalyell who said that it must be unique to have two fathers who both passed secrets to the Soviet Union in 1942 for no personal gain. His book, Scientist Spies, is an explanation of their actions and clearly Professor Broda tries hard to explain the reasoning behind the acts that many considered at the time was a betrayal of America and Britain to the Soviet Union.
Paul Broda's father was Engelbert Broda, an Austrian, and was known as Berti. He was a convinced Communist who had been imprisoned in Berlin and then twice in Austria. He spent some time in the Soviet Union in 1936, but met Paul Broda's mother, Hilde, in Berlin; they married in 1935 and she then joined him in London in 1938.
Alan Nunn May, who later became Paul Broda's stepfather, trained under Rutherford and Chadwick at the Cavendish Laboratory in Cambridge and joined the Manhattan Project, as the Atomic Bomb project was called, in 1942 where he met Berti.
Russia was invaded in 1941 and became an ally of America and Britain, but it concerned both Berti and Alan that the Soviets were being denied information that this research was going on. They were very worried that the Soviets were being treated badly, while they were having to bear the brunt of the war with enormous casualties. It emerged from Russian archives that Berti had been a spy for them for many years, however, Paul Broda stressed very forcibly that this had not been for any form of financial reward - he just thought that this was right. He was, of course, a strong Communist supporter.
Alan Nunn May was very worried about what would happen after the war and thought that if the United States alone had the Atomic Bomb, there might be a pre-emptive strike at the Soviet Union. His aim seemed to be to try to ensure that there would at least be a balance.
He was convicted of breaking the Official Secrets Act in 1946 and sentenced to ten years of penal servitude in prison. He served seven years and was released - much to the annoyance of the United States, but the rules would have had to be broken to keep him in longer and he had been a model prisoner. On his release from prison he met Hilde and they married in 1953 - she had left Berti in 1940.
The book is based on Paul Broda's personal experiences and on all the letters he received from his father and from research into MI6 documents and those of the former Soviet Union. In addition his mother made a tape of events as she saw them. He also has all the letters from Alan Nunn May from prison and used all these sources to write the book.
Among the questions was one which wondered if either man would have been so keen to pass on secrets if all the horrors of what was going on in the Soviet Union had been known at that time. It was an impossible question to answer, but Paul Broda stressed that both men saw the Communist way as being better than capitalism - it is a pity perhaps that that did not know more about Stalin's true character.