Fata Morgana

This is a real genre crosser. We get WW2 bomber operations and aerial combat over Germany. We get travel to alternate worlds. We get lots of action in which the heroes have to survive and overcome impossible odds again and again. We get some really really bad enemies. We even get some romance and a bit of humor.
Basically Fata Morgana is a good story well told and with a very nice ending. It was slightly spoiled for me by a real deus ex machina moment late in the book in which a geeky crewman saves them by taking control of some super advanced technology with no explanation at all as to how he did it.