Displacement

At first, it looks like another one of those "authorial wish fulfillment" tales, where the protagonist finds himself in a relatively primitive society, and, thanks to his vastly superior knowledge and the seemingly miraculous amount of "stuff" he managed to bring with him, he sets himself up as Grand Overlord of his own private domain.

It turns out that it's not the case here.

Yes, the protagonist is intelligent with a good practical bent, and the helicopter he's flying has a bunch of supplies including tools and medicines. But when a weird storm transports him to the Neolithic era, Barker avoids the standard pitfalls.

Holloway does NOT have every single thing he could want (no vegetable seeds - no one on an oil rig is going to be growing wheat or corn; no giant solar recharger for all the power tools; no books on animal husbandry....), and other things (ammunition, fuel) are in limited supply. He actually has to *work* with the tribe he encounters to get things done (I'll pass over the ease in which they learn a common language - one pretty much has to do that), and he keeps some humility and is respectful to the people he encounters.

It does count as erotica, because there's a lot of sex. Barker doesn't go into the details so much that it becomes pornographic; and he actually makes a case that the "free love" on display in the tribe actually helps keep the tribe together and help establish a social hierarchy. And the frequency with which he has lovers is also justified.

That becomes important later in the story, when a pioneer family (from the 19th century, it's assumed) is brought into the area by the same sort of storm. The husband and wife are extreme religious conservatives, and Holloway has a heck of a fight on his hands to get them to understand the social dynamics of the tribe. It winds up leading to what can only be described as a gang rape scene. It isn't as violent as it could have been (thankfully), and Barker did set out the argument that the act was required in order for the couple to become part of the tribe. You don't have to buy his argument, naturally, but he did make one that is both internally consistent and fits with the milieu he created.

"Displacement" is a good value, and much better than similar works by "professional" authors (*cough* Leo A. Frankowski's "Cross-Time Engineer" series *cough*)