As one might expect given the author and an original publication date of 1955, this is classic science fiction. There is an intricate plot, big ideas, time travel paradoxes (paradoxii?) and all the rest. It is, as one would expect from the genre, a bit short on beautiful prose and rich, multidimensional characters. Because it is old, and you can almost feel yourself brushing the dust off as you read, you get the added fun of seeing what Asimov gets right and gets wrong in his implicit predictions about technological progress.
Overall, great fun if you are into this sort of thing. There is a reason they are reprinting this in 2013.
Recommend for science fiction sorts.