It’s Frankenstein meets The Wolfman meets H.C. Andersen meets Jewish folklore meets aliens, set in Germany. Ok…
The 8th Doctor and Lucy fail to go to Alton Towers and instead end up in the Black Forest, just as the infamous Baron Teufel (german for devil) and ducal emissary Lügner (german for liar) have been attacked, and the latter killed, by the legendary Beast of Orlok.
Coincidentally, two young siblings, Hans and Greta Tod (german for death/dead) are then also drawn into the plot, while – equally coincidentally – a ‘mystic traveller’ named Judah (hmm, as in Rabbi Judah ben Loew, of the-Golem-of-Prague fame) and his friend Wolf are sneaking around the area.
Bits of Frankenstein, The Wolfman, Hansel and Gretel, Jewish folklore and some science fiction later, and you’ve got yourself a Doctor Who audiobook.