This book would have been a good, fitting ending to the series (as everyone knows, it was originally written as the final book) as the treasure hunting adventure and the Mediterranean locations manage to live up to the high standards of the premises and settings of the previous two books, if not to the exceptionally high standards of the first three.The only problems I have with this book are that the extremely convenient departure of Mrs Mannering and the breakdown of the ship's engines are far too contrived and convenient even to seem right in an Enid Blyton story, and that Mrs Mannering is cast in the unenviable role of stick-in-the-mud, ball-and-chain mother far more than in any other book in this series. This is an unfortunate role that many Enid Blyton mothers are forced to adopt at times, although at least there is some precedent for it with Mrs Mannering, unlike with (for example) the mother character in the "Secret" series, who undergoes a complete personality change in the final book.Was it worth Enid Blyton's time and effort coming back to write two more books in this series, or should things have been left alone after this adventure? I seem to remember that at least The Circus (if not also The River) is right up there with the best ones in this series, and I'm very keen now to read on and find out.
