I've come to really like the Joe Pickett series by C.J. Box. Pickett is a good hero. Strong, taciturn, devoted to duty and a highly moral man, he loves his wife and family, and his low-paying job as a game warden in beautiful, wide-open Wyoming.

Where odd murders happen from time to time, at least in this quietly involving series. (One of my favorites, from ``Savage Run'' in 2002, featured an exploding cow that may have killed an environmental activist.)

His fourth outing, ``Trophy Hunt'' (Putnam, 323 pp., $24.95), is lean and strong of plot but takes us in surprising directions -- ``woo-woo stuff,'' as Pickett calls it: ritual mutilation of animals, and crop circles.

On a fishing trip Pickett comes across a dead bull moose in a meadow. Part of the moose's face and certain organs had been neatly removed, as if with a scalpel. But although the moose has been dead for some time, no wolves or coyotes or other animals have touched the corpse. And there are no immediate indications of what caused the death or tracks around it.

Soon, some cattle are found in the same condition, and eventually, humans start meeting similar deaths.

A task force is formed, with the local sheriff, the FBI, state cops and Pickett. Some people start talking about alien visitors and other goofy theories, but Pickett discounts the ``woo-woo'' ideas and just keeps plugging away, looking for information.

Meanwhile, his wife, Marybeth, has been working as an accountant to supplement Pickett's modest income. One of her clients is Logue Realty, run by a new couple to the small town. Their daughter, and the Pickett's daughter, Lucy, become best friends -- and conspirators, in the way of 7-year-olds. For instance, sneaking into the creepy abandoned buildings behind the Logues' historic home, which they are refurbishing. The entire Pickett family, before long, is in danger.

There's a ton of stuff for Pickett to think about. Wyoming, after years of modest existence, is suddenly important for its stores of underground methane. Which leads to many real-estate and mineral-rights issues. And the process of getting the methane out also releases a lot of water, which leads to other issues, such as salinity levels and amounts of chemicals. And -- more in Pickett's realm -- a grizzly bear has left its range and is wreaking havoc on a path that seems to be leading it into Pickett's territory.

Throw in a publicity-seeking UFO scientist, a lot of eccentric Wyomingites and the stress of having to cook dinner himself because Marybeth has been working, and Pickett gets a heck of a headache.

But for readers, it's a good ride. Pickett never gets so wrapped up in his investigation to ignore another beautiful fall sunset in the mountains, and he never does anything to disappoint us.