I'd like to thank Madam Broshkina for the version I downloaded from MR for my CyBook. The cover was lovely, and the quality of the text excellent.
As to the story, I found it an easy read but not a particularly gripping one. Within the first few pages I was a bit confused about the way Norton handled a pilot suit - at one moment it seemed outlandish, and the next it was treated as an everyday item. I don't know whether this was supposed to presage the alien suit we encounter later in the story - but I suspect nothing so subtle was intended.
The plot stretches the reader's disbelief, and there is very little attempt to explain the scientific basis of the time travel. Similarly, there seemed little attempt to give any depth to the characters. Another drawback is that it is the first in a series, so the resolution is incomplete.
There were a few moments of impressively imaginative writing that raised it above the level of average SF pulp imho. I'm glad I read it, but it wasn't enough to spur me into reading the rest of the series. 6/10