The web comic Flying Fortress tells the story of a WWII B-17 crew who goes on one final mission to bomb Hitler's secret base deep in the heart of the Black Forest of Germany. Upon their return trip home they are shot down and crash land in a mysterious land stuck in what appears to be the middle ages.
Knights, Nazis and plague-ridden soldiers permeate the land. Can the crew find a way home or are they stuck in the alternate dimension forever?
You can read Flying Fortress online, for free at FlyingFortressComic.com