I love Cassie Oldfield and Walter Shaws, the forensic geologists Dwiggins introduced in Badwater. Taking the geology, mineralogy or geomorphology of a crime scene as evidence is a fairly new idea in criminalistics, and this series does a great job of spinning it into a good yarn.
In her latest novel, Cassie and Walter get a call for help from a cop in Morro Bay, a small fishing community-slash-tourist destination on the California coast west of San Luis Obispo. Detective Tolliver has an anchovy-fishing boat with a missing owner and little in the way of evidence, beyond some grains of sand. Cassie is
Grateful for a cop who recognized rocks as evidence, who treated them with the same respect given to fingerprints or cigarette butts or bloodstains or what have you.
Like any fishing community, this village has a rumor mill that soon informs the residents of the reason for their presence. Sandy Keasling, the spiky captain of a whale-watch tour boat, with her deckhand Lanny, Jake "Captain Kayak" who runs a paddle-rental service, and the sinister Oscar Flynn with his two PhDs and giant chip on his shoulder, and Tolliver himself, will all become enmeshed in the net of rumor and speculation.
We have an injured scuba diver, yes, and a suggestion of foul play in some squid ink stains, but perhaps there is no criminal. There is a red tide, and plenty of creepy clues in the water. Cassie and Walter will need to bring all their abilities to bear, researching and making connections outside their area of expertise, to solve the mystery of Morro Bay.
As humans, we like to find someone to blame. One of the greatest appeals of anthropogenic global warming is that it gives us a party or category of actors on which to land the guilt for the consequences of climate change, and narrows the list of events that are still considered an "act of God." Lava flows, for example.
Dwiggins has given us yet another mystery that blurs the lines between the true act of God and the criminal deed.