The Pilot in the Edelweiss #1-3 (2012-2013)

1917: above the trenches of the battlefields in Northern France and Flanders, where desperate French and disillusioned Germans murder each other in the mud, are the French and German flyers creating something new. They fight merciless duels over the front, day after day and the outcome is always the same: one pilot lives, the other burns. Then one day a German plane appears in the sky: an Albatross, a biplane with a beautiful Edelweiss on the upper-wing. The Pilot in the Edelweiss, as he's instantly dubbed, sows death and destruction among the Stork Squadron, the elite flyers of the French Air Force. Why is the intrepid French ace, Henri Castillac -- recognized by everyone as a fine dogfighter -- so startled when the Edelweiss joins the fight? Does it have something to do with a nasty secret Henri shares with his brother Alphonse? And why was Alphonse, a first class pilot like his brother, thrown out of the Air Force?
And what actually happened on the Pont de l'Alma during the spectacular flood of the Seine in January 1910?