While Gethin's mother spent most of the Second World War cracking German codes at Bletchley Park, his father was a conscientious objector. As he grew up, and his mother maintained her Government-imposed silence on what she had been doing, Gethin's father was voluble on his pacifism, and Gethin dreaded the question 'What did your father do in the War?' The answer 'Nothing' seemed shameful. Now, with his mother's...