The Running Heroine

The "Running Hero" is a character who appears in a series of books. Sherlock Holmes, James Bond, even Miss Marple can be described as Running Heroes.
In my crime novels - 20, so far - there are several running bit-part players, such as the solicitor whose client-list includes otherwise unconnected characters. The fact is that even my stand-alone novels are nearly all set in the same world, and some of the people  in them  appear in more than one book, not always as the central character - for example, the archaeologist Professor Thea Crawford, who is the heroine in THE ONLY SECURITY and takes a minor role in several later books.
One of these not-quite-heroines is the psychiatrist Dr Fidelis Berlin. Several critics and commentators have called her my most interesting character, and I found myself wondering if she/I could discover more about her background.  How did she come to be the unaccompanied, unidentified infant who arrived in England on a kindertransport? I didn't know the answer myself , but then, I never do.  If I were not making discoveries as I write I'd have no interest in doing it..
The book that answers those questions  is coming out in June.
 DEAD WOMAN WALKING tells the story of Fidelis Berlin, and also reveals what happened to some of the characters in my very first book, A CHARITABLE END.
It was first published   40 years ago.