Okay, having finished the book, I can quit being coy and tell you that what I was actually reading was Deadstick, the 1991 debut novel by Terence Faherty. And my verdict is that it's quite good, especially for a an author's first time out.
The lead character, Owen Keane, is a former seminarian who didn't make it into the priesthood. In this book he's working as a researcher for his friend's law firm. The friend, Harry, assigns him the project of investigating a fatal plane crash from forty years earlier, at the behest of one victim's very wealthy recluse of a brother.
I've read enough detective novels to know that there are cliches, tropes, call them what you will. Things that make storytelling easier and which the audience doesn't mind, might even prefer. Faherty is good enough to avoid a lot of them and to play with them when he does use them.
For example, I was expecting there to be at least one scene where someone tries to scare Keane off by shooting at him or at least beating him up. (It's established that he's not really a fighter.) The greatest physical threat, though, comes when a Pine Barrens storyteller he's looking to for answers takes him out to the middle of the woods and just...leaves him there. Their scene together just before this may be the height of the novel.
There are a bunch more books in the series, last one so far being published in 2013. It seems to have been mostly overlooked. Faherty has won the Shamus Award but for a book in his other series, about former actor Scott Elliott. The Keane books seem ripe to be discovered, though.