Read this a kid well over 20 years ago and not in English, so bear with my recollections. I would like someone to identify this book and its author.
The story basically is of some guy who is driving somewhere and muses on the topic that the road that he is about to travel is known for some mysterious vanishings every something-years. And guess what, as he is driving down that road a cloud rolls over the road and then he finds himself crashed into a tree, I think in some unknown place, a forest.
He starts walking and witnesses some cigar shaped objects duelling in the sky and eventually runs into a group of WW2 British (RAF?) servicemen who say that they've been stranded there for 4(?) years or so and don't realize that it's been 20 years back on Earth. They much rejoice on learning of the defeat of the Nazi Germany. There is some discussion among the characters that the world they are in is the fairy world of old legends. There are also some mysterious natives, one of whom is known as Herald/t(?). I think they look kinda human but are not.
One of the British party's original members, a woman, has fallen under that guys influence and underwent some procedure that basically turns her into one of them, with corresponding physical and psychological changes, these changes come about gradually and she still retains some of her humanity. They also have some weird cities, which the main character describes at one point as unusually empty as there is no one in the streets. Eventually I think he starts developing psychokinetic powers for some reason or realizes that he's had them all along.
In the end for some reason he sides/fall-in-love with the defector-female and, I think it's-a-literal-bite-on-the-apple, chooses to become one of the natives.
I think there's a moment towards the end of the book during a confrontation of some sort, when the main character has his hands tied behind his back against a tree and he has to "reach" for a knife with his psychokinesis.