http://www.bbc.com/news/world-us-canada-42314701

The summer before university, my dad and I went for a drive in the old Volvo - just the two of us, something we never did. We buckled our seatbelts, and kicked up dust on the gravel lane.

"Peter, it's time to tell you about the family business," my dad said as he tapped his fingers on the wheel waiting for a red light. The light turned green and we pulled out onto the main road.

"Espionage."

My father had a deadpan sense of humour, but if this was another dad joke, I thought, it seemed very elaborate and not very funny. As we drove through our town, a suburban huddle of strip malls and telephone poles, he told me he had worked undercover for the CIA for almost 40 years.

When he didn't smirk and the silence became dense, it occurred to me that he was serious.

"Does mom know?" I asked.