Man vs. nature. Man vs. man. Man vs. himself. It's all there. Especially the nature part.
Remember the last part of Cold Dish, the first book in Craig Johnson's Walt Longmire series? In which Walt -- wait, not Walt, make that "Crazy Walt" -- Crazy Walt heads up into the mountains after a bad guy? In which there is much suffering on Walt's part and he sees "things"? This time, instead of just a small portion of the book devoted to Walt heading up into the mountains after a bad guy, Craig Johnson has devoted the whole book to that plot.
Read Dante's Inferno before you read Hell Is Empty. At least read the CliffsNotes version. Johnson not so subtly draws parallels to that story. Instead of Dante's trip from the dark woods down into the circles of hell, Walt journeys up from the forest into the cold reaches of the hell he finds in the mountains. There are even Wyoming versions of Beatrice and Virgil.
The whole gang you've come to know and love -- Vic, The Bear, The Basque, Ruby, Cady -- is there but just in flashes, because it's all about Walt and the mountain and the man he's after.
Briefly, a prisoner, Reynaud Shade (hello!), escapes during a transport exchange in a fairly remote area of Wyoming. Shade is a bad, bad man who sees "The Old Ones" and claims he knows Walt does too. Taking hostages, Shade heads up a mountain. Taking a soggy sandwich and a cell phone that doesn't work, Walt heads up after him. A monster of a blizzard and an incongruous forest fire are impediments. Hypothermia and concussion are nuisances. Through it all, Walt is steadfast and determined to make a final showdown on the mountain.
Boy howdy, it's a page turner. It's also graced with Johnson's humorous turn of phrase, even in the most dire of circumstances, and a sweetness as Johnson shows us the strength and determination of the heart.