It's also just a dreadfully boring movie. At just over 80 minutes long, it feels like it's twice that long. You know a movie is bad when the commentary track is more interesting than the movie itself.

In this movie we have a young scientist who is raising fake funds for an Atlantis mission, worries that he didn't sell enough books to cover the cost of the press conference, but owns a billion-dollar sub. After being taken in by some seductive decoys, he is convinced to look into the destruction of an undersea base (located under a drilling platform). The investigation takes his sub to its depth limit. Enter coordinated shark attack.

Soon, ala James Bond, said scientist finds himself aboard a secret sub where they have been developing the attack sharks for the past 20 years. He and his sidekick (a brainy, busty, oceanographer) baffle the crew with bluster before having to run for their lives. Eventually we get to a cheesy ending involving reunited families, amazing discoveries, and credibility thrown out the window.

There are some odd bits to this film. One is the offshore drilling platform. At what should be where the shaft meets the seabed, there is an installation that looks like an underwater city (mistake or unexplained secret base? My guess is the film makers didn't know anything about offshore drilling). There is also the shark tank. It is in the floor of the research lab with open water. It also extends up in front of the lab so than an impressive window can be opened into it. I shudder to think of the air pressure required to pull off this feat.

The story revolves around Guarnaccia's gradual unravelling of a decades old feud and it's tragic echo in the present.

As ever with Ms. Nabb the story is told with wit and compassion , there are no car chases ( there is a bus ride in the rain ), no shoot-outs ( in 20 years Guarnaccia's Beretta has remained firmly in it's holster ) and no lack of compellingly drawn believable characters.Yet again the atmosphere of Florence is brought out ( apparently ) efortlessly and adds enormously to the success of the book.