Where Eagles Dare

Where Eagles Dare - Alistair MacLean Cracking WWII tale from Alistair MacLean, which everyone will be familiar with from the film.
Lots of action, well written characters, and plots within plots within plots as a crack team are sent to rescue someone from the German armies main base at Schloss Adler.

Plenty of obstacles get in their way, and the location of the castle makes it even harder to get in and out.