What Is Henri's Motive?

In World War I, many men are gone. They're fighting or they've died at this point. In the war, there are a lot of widows and Henri is able to take advantage of this. And what's interesting is he selects women who don't have a lot of money. Their husbands are gone. So that's where as we get deeper into this, the question of motive really does pop up for me. It was a woman named Jean Cusche. She was 39 years old widow. She was a seamstress and she had a 17 year old son named Andre. But finally she got engaged to on re even though of course he was going by this alias. He