Police inspector Louis Janssens, 59, and his secondcousin Paul Alix, 61 - a retired industrial mechanic - also find it hard to keep their emotions in check when they talk about their grandfathers, orphaned brothers who fought together at the Yser and in Ypres.
We meet David as he arrives in Poland to visit his 75-year-old secondcousin, Maria, whom he met once as a child but typically, doesn't recall the experience.