Not strictly a prequel to the 'Wolves of Willoughby Chase' sequence (our young hero Owen Hughes re-appears around the time of the plot to slide St Paul's Cathedral into the Thames at a coronation), 'The Whispering Mountain' can nevertheless be enjoyed as a standalone novel as well as filling in more of Aiken's alternative history of the world in the early 19th century.

Set in and around the western coast of Wales, the tale features elements of Welsh mythology, Dark Age history and traditions of Nonconformism and mining, along with several other typical Aiken themes such as Arthurian legend (revisited in 'The Stolen Lake' for example), slavery underground (as in 'Is'), mistaken identities (as in 'The Cuckoo Tree') and dastardly villains (as in all the titles of the sequence). Although convoluted, the plot draws you along to the inevitable conclusion, and as always Aiken doesn't shy away from death even when writing for a youngish audience.

Of especial interest is the Welsh setting and use of language and traditions away from Aiken's usual specialities of Yorkshire and the southeast of England. Living in West Wales, I was particularly intrigued to see aspects of different real localities transmogrified to suit the story and the conceit of an alternative geography of Britain; and characters' use of Welsh phrases (there is a glossary at the end) and idioms when speaking English struck chords for even someone like me with only a passing acquaintance with the language. I also loved the puns, such as the placename Pennygaff which, although it has a Welsh look to it (real placenames include Pen-y-fan and Pen-y-Bont, literally Mountain Top and Bridgend respectively), is actually taken from the name for a type of popular Victorian theatrical show.

All in all, then, this a book worth reading for its liveliness and inventiveness even if you're not a dyed-in-the-wool Aiken fan.