13. With assistance, von Bek escapes from the concentration camp. He is then taken by car to an exit from this world into another via a cave close to which German town?
From Quiz The Dreamthief's Daughter
Answer:
Hameln
Ulric is assisted in his escape firstly by his sword, although he is not sure how it came to be in his cell, then by a female archer who turns out to be the titular character. Subsequently the two of them are met by an Englishman, Captain Oswald Bastable who drives off through Germany.
Hameln is better known in English as Hamelin and it seems an appropriate place for a link to another world. See the story of the Pied Piper of Hamelin for another example.
Back to the story, the trio open and enter a cave, closely followed by Gaynor, Klosterheim and a troop of the SS. At first this is a subterranean world, but at other times seems to be a totally new plane of existence. Eventually it is identified as Middlemarch, or Mittelmarch in German, the borderland between human and fairy kingdoms.