Aces: Curse of the Red Baron

It's World War I. Amidst the bloodshed, a British flying ace and an American infantryman steal a map from the body of the Red Baron, a map they believe leads to his lost treasure. The two adventurers desert their posts and embark on a remarkable quest that leads them into enemy territory, past vanishing islands, secret organizations, and a confrontation with the ghost of the map's previous owner ― the Red Baron himself!