oberstleutnant von beneckendorfs wife ( now in her early nineties ) sat at his desk all afternoon reading his diary , clasping the rosewood box that held the going away present that she had given him as she had bid him farewell that last time ( it was a fountain pen ) ; and leutnant angerns son , who had just worked out that he had been born whilst his father was actually airborne on his last mission , talked me into taking him up for a flight in his fathers aircraft .