I presume this is a First Edition because this title is listed last in the list provided in the book.  I realize Hardy Boy First Editions are very specific, and this list placement is not the only edition point to identify a First Printing, so rely on the pictures for other issues such as the board color, endpaper, and so on.  Overall in GOOD OR BETTER CONDITION.  The boards are very clean with little to no edge or corner wear, faint corner bumping.  Very solidly bound with no endpaper cracking.  There is a faint hint of a price on the free front endpaper, upper right hand corner.  There is a previous owner name stamp on half title page.  There is a pinhole impression on the page starting at the free endpaper and extending to about the first page of a book.  It's as if a tiny sharp pebble was in the book and pierced a fine hole in the first few leaves of the book.  It can be seen above the stamped name of a previous owner in the listing photos.  A few dog-ears were straightened.  214 clean and solidly bound pages.