The End of Eternity by Isaac Asimov

This is one of my all time favourites. It was one of the first science fiction novels I ever read and because it stems from my earliest experience ofSF, I cannot judge if it is still comparable with modern SF but I think perhaps it is. The love interest is not graphically described and may seem a little tame by today’s standards and considering it is Harlan’s prime motivation for the events that follow his meeting his lover, this may seem understated. But hey, we are all grown up and we don’t actually need to be told what happens when two adults of the opposite sex go into a bedroom together do we?

The background of this story is that in the future, when time travel becomes technically possible, a group of technocrats set up an organisation that uses time travel to control history by changing events here and there to remove any possible trends that will cause war or suffering.
This organisation is known as Eternity and it is very tightly controlled by a group of exclusively male, monk-like men living outside time in an artificially generated time tunnel that extends from the 27th century into the distant future when the sun goes nova.
Time technicians working for Eternity can travel up and down this time track in lift like capsules referred to as 'kettles'. The kettles can only go as far back as the 27th century, when time travel was discovered and so we ‘primatives’ in the 21st century have no knowledge of Eternity.
The distant future beyond the 70,000th century is not accessible to the Eternals either, because the inhabitants of those distant eras have somehow prevented the Eternals from travelling that far into the future.

So there is a mystery, who has done this, are they human? It is only known that the future people do not want the Eternals messing with their history.

The Eternal’s self imposed task is to keep history safe for humanity and remove any social trends that do not fit in with their idea of what is best for Mankind as a whole. You soon realise this autocratic control is stifling humankind and much that is good is lost by this meddling, in particular space travel is never developed, since it seems to often lead to war and so is never allowed to come into being. Any social trend deemed to be too dangerous to mankind is surgically removed from history by the sterile old men who run Eternity.

Into this rigid womanless organisation is recruited one Andrew Harlan who is trained as a time technician. In the course of his duties he encounters Noys Lambent, a girl from outside Eternity and falls in love. Noys comes from a reality that is due for a historical change that will either prevent her from being born altogether or change her so much she will not know Harlan. So thinking with his gonads he immediately abandons his principles and breaks all the rules so that he can keep her safe from this change by hiding her. At first this is in the deserted sections of Eternity close to the hidden centuries.
But Harlan soon has to escape from Eternity altogether and his only chance to save Noys and himself is to go back to the time just before the start of Eternity where no one can follow him. In doing this he unwittingly prevents Eternity from being started in the first place, hence the title. Because of this, mankind is free to have wars and go into space before the aliens get there.

This book stands alone but it could be argued that it is the pre cursor of the Trantor series because Trantor could not exist if Eternity had not been ended. With Eternity around, mankind never gets into space until other alien species have already claimed all the real estate out there and put up no trespassing signs, so Harlan is responsible for creating a new reality where Trantor becomes a possibility.

Altogether a very readable book with a nice twist at the end that Harlan is able to exploit to achieve his aims, whilst Noys has a secret that is not revealed until close to the end too.