From the introduction:
Earth, the 20th century. A time of technological innovation, societal changes, upheaval vast and pervasive enough to see maps redrawn… and three wars enveloping the whole world.
That’s right, three. Two hot, and one Cold. And it’s the third one that concerns you here. You’re going to the world of Spy Thriller novels, jumper. Not any specific work or even any specific author’s works, but a generic world comprised of elements from all of them, or maybe one where they’re all taking place at the same time.
The default time and place are Cold War era Earth, but there’s no real restriction on when or where this jump takes you. If you think you can have an interesting Spy Thriller adventure in Ancient Egypt or Coruscant or wherever, it’s all up to you.