Snaking into shops next February...The Serpent Pool

I've got my hands on the new Allison & Busby catalogue and one of the long awaited delights in it is Martin Edwards's new book in his Lake District series: The Serpent Pool. The cover below is from the US edition, published by Poison Pen Press and which is also published in February.

Synopsis: DCI Hannah Scarlett is determined to uncover the truth behind Emily Friend's mysterious drowning in the Serpent Pool.

But Hannah's distracted by a new sergeant with a troublesome reputation, a new house, and new cause to doubt her partner--second hand bookseller Marc Amos. One of Marc's best customers has been burned to death in the converted boathouse filled with priceless books.

Then Hannah meets Louise Kind, sister of the historian Daniel Kind, who has just returned from America to work on a book about Thomas De Quincey and the history of murder. How are all of these elements related?