Another wide ranging adventure centered around a lost ship, whose final resting place is unknown. In this case, it is a WWII British submarine, the Upholder, which was lost with all hands in the Mediterranean after a secret mission in the early 1940's. Maggie Riley and Cole Thatcher, using his father's cryptic notes, search for the wreckage and a potential priceless artifact. Of course, at least one other organization, with nefarious intentions, also wants the artifact. The search area covers the Med from Turkey to the shores of Tunisia, with a side trip to Rome. There is some action, but a lot of time is spent traversing the Med from Turkey to Malta to Crete to Djerba, and points in between. This is in interesting read, but just doesn't have the spark that CIRCLE OF BONES and THE DRAGON'S TRIANGLE had.