The ending of a book...

[The_Doctor]

You could leave it open for a sequel.

[Radier]

It must end somewhere. Two books are planned for now. As a said, the problem is how to end the second book... Which side shall win? Good, bad, noone?

[JimBob]

Heroic defeat in the face of adversity can make good reading. So long as the bad guys get a licking on the way to victory and the good guys don't roll over and do the whole heroic last stand thing it works. Honestly I've always enjoyed movies and books where the cavalry arrives late, or gets stopped. There's something that appeals to some tragic view of heroism