The Magician's Legacy: Peter Sharp Legal Mystery #7

True mystery fans know that the best kind to try and figure out is the "locked-room" variety, and with this book author Gene Grossman has created what has been called the best locked-room mystery of the century - because the locked room is an unpenetrable safe room that must be opened by a crew with blowtorches.

You'll be scratching your head trying to figure this one out.