Actually pretty good. It was the historical and technical things that got to me.

This is supposed to be set in 1951, but the helicopters are clearly CH-47 or variants. The program for that craft didn't start until late 1956, with the first ones to fly in 1960 (give or take a few months)

Most of the other things are along those lines, but this *is* fiction - with vampires, werewolves and other things, but the writer could have been more accurate with the mundane tech of the period.