In 2003's "Winterkill," Wyoming game warden Joe Pickett's foster daughter, April, was killed. Or was she? The child of a cult-following, dysfunctional mom may be sending text messages to Pickett's daughter, Sheridan, 17. And the wound from losing her the first time has never healed; he's determined not to blow what might be a second chance.

The text messages, by the way, are doozies: The girl seems to be traveling with a father-son pair of serial killers who are crossing the country killing people who have an unusually large carbon footprint. It's an unsettling, violent way to save the planet from global warming, but with a dying gangster who just wants to please his spoiled and nasty earth-activist son, no act may be too outlandish.

In an unusual twist, Pickett takes his daughter along to help him track the girl who could be April. And they team up with another character who's well-known to folks who've been reading the Box's Pickett series, now nine books deep.

"Below Zero" is the best of the series I've read so far. It ties a controversial modern worry (global warming) together with other issues in a most unusual fashion. It's fast-paced, the characters are interesting and for the most part well-developed.

By Lois Collins