The technology is a little weak but the idea of progressively leaping back in time create some interesting interplay among generations of the same individuals. The inclusion of a Nephilim and prehistoric dinosaurs makes for another level of interesting plot. The climax is far-fetched and some of the details and implications left cloudy. The authors attitude towards religion is also ambivalent. But in my opinion it’s a better read than Robertson’s subsequent books the others which builds directly on this one.