You must be patient when you read this. It is a reader's book. Not to be. skimmed. Two worlds - parallel. Our Earth and para-Earth. Different laws of physics but somehow one is able to reach across to the other and both are helped. Then there is a problem. But a third world is found.
Part 1 occurs on Earth
Part 2 occurs on para-Earth
Part 3 occurs on the moon.

Have patience. It really is good.
Except the last few paragraphs. Could of done without the lovey-dovey stuff. ( )

Story: 8 / 10
Characters: 8
Setting: 7
Prose: 7

A truly remarkable book. The gods are brilliant creations and the humans aren't bad either. Really captures the fight for academic and scientific contribution. The only real way to improve the book is to lengthen the ending. ( )

I really enjoyed the first part and I very much admire his ability to write characters that feel real.
They are selfish, they are flawed but I like them anyway because I can relate. The struggle of characters recognizing their own flaws but being powerless to stop themselves from being influenced by them is something that very few authors can pull off successfully.

But I just couldn't get into the second one on the other side.
For many, it might be really fascinating to follow the imagination of a fundamentally different species from their perspective. These things might seem new, strange and fascinating to others but for me, it took no time to acclimatize to this new frame of mind and I just don't feel the fascination necessary to carry me through this incredibly long and repetitive introduction to these beings. I just didn't experience any real awe. And apart from that, there is just nothing happening. Call me impatient or unappreciative if you like but for my taste there just isn't anything interesting happening and all this information about this other species seems completely irrelevant.
I love good worldbuilding if there is a point to it but in this case, it does nothing for me apart from destroying the pacing.

What a tedious book. Look, get over the hagiography already; Asimov formed great ideas, brilliant conflicts between technological development and social evolution, and loved conspiracies but tended to write thin characters and absolute crap dialogue (I remember "The End of Eternity" as particularly guilty). This book features all of those in spades.

Interestingly, it's the humans in Parts I and III that are two-dimensional, irritating, and converse in leaden, expository infodumps. Part I is marred by the stiff posturing of "scientist" caricatures, Part III hampered by weird gender politics and the author's repetition that Lunar residents are immodest. This has not aged well at all.

Part II's aliens are the only truly fresh and original content. Asimov presents aliens with a truly alien biology whose life cycle dictates their own cultural development; the psychology of the main individuals we're shown is very consistent and allows for an engrossing story. This is the only really good SF part of this fix-up novel.

Once and done. ( )

The book is a real page turner but I thought the ending disappointing. ( )