This is a unique one for Asimov, and not connected to his usual fictional universe. Ironically, this is his first book I tried to read, in Malayalam translation, no less! But either the translation was bad, or the story was untranslatable, or I was too young for it... I dropped it after a few pages. I am glad I did, because I could read the original afresh.
This story is about a group called Eternals who travel outside of linear time, stepping in when required within the time-stream to make things "better for humanity". Well, it all ends up rather like America making the world safe for democracy.
I don't remember much other than the main character almost meeting himself as he enters the time-stream from different points. For some reason, this is considered a disaster. I don't know why. If I get chance, I would like to go forward and meet my older self, just to know how I made out.