A Cold Copper Moon carries two plot lines. The first is a flashback to Maxie's kidnapping. He will either be found or not in this latest book--it happens in the Winter. Thus the name: A Cold Copper Moon.
The second major theme is Big Oil--and specifically about the encroachment of the oil companies in south Florida. Drilling is going on in the Everglades and there is a move to open up sections of the eastern region of the Gulf to oil exploration. Cooper gets caught in the middle of the Big Oil story and people get killed in the process.
And so it's a cold time in South Florida. And the Moon, cold and copper in these winter months in the tropics, is the watchman.