Pandemic Audio: Burning Bright by Nick Petrie, 2017, Wisconsin Digital Library.
Second novel with drifter-dude Peter Ash. A recap: Ash was an infantry officer in the Marine Corps with several war tours. When he was discharged he ended up with a severe claustrophobia that makes him unable to endure being inside any buildings. He has been living in his pickup - an old one with a big windscreen window that makes him feel more outside - and working outdoor jobs like construction. He also has retirement or disability money (I don't recall which. Maybe both. Doesn't matter.) from the Corps.
Ash has been working with a trail building crew in the redwood forest of Northern California. When the job ends Ash starks hiking. While taking a break on the trail he downs his pack and leans against a tree. A bear shows up Ash climbs the tree. The bear tears apart all of Ash's belongings and sits at the bottom of the tree. Ash figures, "Fuck it" and starts climbing with the intention of traversing branches until he can get several trees away from the bear.
Ash finds a hanging climbing rope. Ash figures "Fuck it" and climbs the rope. Ash climbs more ropes into the redwoods and traverses tree-to-tree until he finds a woman with a gun living in the trees. Tree Woman's famous computer professor mother was killed and people are trying to kill Tree Woman. Ash figures "Fuck it" and he and Tree Woman team up to fight the power.
Anyhoo. Ash and Tree Woman get lovey-dovey. The bad guy's are ruthless mercenaries. Ash is a ruthless killer. Ash and Tree Woman move around the Pac Northwest figuring things out with some cat-and-mouse and death.
1. These are knight errant novels. An easy comparison is to Jack Reacher but Ash seems more ruthless somehow. And that is saying something.
2. Pickup truck love.
3. Eccentric mathematician love.
4. Easy chair tourism with Ash and Tree Woman moving around the forests and a couple cities.