The book is set at the tail end of the 20th century and the first couple of decades of the 21st. Kilian presents us with a bleak dystopian vision of a decaying society on the brink of collapse. At the last moment a technique for absorbing and processing huge amounts of information was discovered and human computers called `trainables' were born. Trainables were used to prop up the tottering fabric of society, but even they couldn't stave off the inevitable collapse. The world was saved by a freak lab accident which led to the discovery of alternative earths occupying different positions in time, both past and future. The idea of accessing these separate earths is a good one (if a bit clichéd) and the idea is well implemented in the story. The books main character is Jerry Pierce, a highly trained special agent for the Intertemporal Agency. He specialises in the `Black Ops' projects such as assassination and `punitive' expeditions. At first sight he seem to be as ruthless and soulless as a cyborg. Later on in the book you learn the reason why this appears to be so and he is revealed to be a (marginally) more sympathetic character. One of the core premises of the book is slightly suspect. Being a `trainable' will surely allow a person to absorb a great deal of information quickly, but this doesn't mean that the information can be used intelligently. At least two additional skills are required to do this, the ability to cross reference the information and the ability to form opinions based on this collated information, without these skills all you have is a huge mound of undigested data. Kilian glosses over this in the book and as a result the trainable are seen as near genius figures. This book was originally published in 1978 well before the first PCs were created. As a result some of the technology used (microfiche) is a little dated. The plot flows well and does manage to hold the readers interest and would probably make a great action film ( along the lines of 12 Monkeys and Terminator 2). I enjoyed this story and look forward to reading more chronoplane adventures from the same author.