In order to pay the taxes, he initially decides to auction off the mansion and its contents, including a massive computer (the Generalized Nonlinear Extrapolator, or "Genie").

He hits on the idea of using its capabilities to create an elaborate hoax ... a fake time machine.

Accordingly, he asks the computer to show him "real, three-D, big as life dinosaurs and plenty of em - and how about a four-wall presentation?"

Even when they manage to return to the present, their actions in the past have altered it completely, but they are able to use the computer to (perhaps, more or less) restore everything to the way it was.

Algis Budrys gave the novel a mixed review, writing that while Laumer did many things well, his attempt to bring widely disparate elements together is unsuccessful, ending up without "even one whole book to show for it".