Since the novel starts in 1970 and then goes into the future, it's easy to forget that this was written in the 50s. Being written much before the computer era, and being set in the near future, which is actually our past now, it suffers from retrofuturism, like a lot of old science fiction. So of course expect no internet, no modern computers, no modern social values... So a modern reader has to be able to see beyond those obstacles in order to enjoy this fine story about time travel and the development of limited types of AI. In fairness to Heinlein, although he did not get the technological details right, the general idea about what kind of tasks AI can do is accurate.

Anyway, other than that, the story is interesting, very readable and fast-paced. It's told in first person by a very creative engineer, and it features industrial theft, various types of time travel, cats and a love story that is actually kind of creepy. There's a kind of optimism and charm in the way the main character is always inventing something, and cares much more about the creation process itself than about the business element.

Being written during the early stage of Heinlein's career, the narration is tight and focused, and I enjoyed it, much more than his later work although it's not my favorite Heinlein novel. ( )

A solid enjoyable read. A little slow in a couple spots. I wish Heinlein would have spent more time on the character's relationships and motives. Even now I'm not sure exactly why the protagonist, Davis, did everything he did, but I sure enjoyed the ride.

It also had a really fun happy postmillenial, and almost ethical-judicial end to it. It's good to have some hope for the future. Never stop looking for that door to summer. ( )

This story is definitely amusing fluff, which seems right for a short sci-fi novel written in the 1950's. I best liked Pete the cat and that the story does not take itself too seriously. Its attitude toward its female characters is pretty awful, though, even taking into account that was written in the 50's. I have the uncomfortable feeling that RAH was a founding member of the MRA society. The ladies are all evaluated first on their physical attractiveness, and I say "ladies" loosely because this also applies to an 11 year old girl. The only smart woman is a "man-eater" caricature, who gets her just desserts as she ends up old, ugly, man-less, and poor, but still desperately trying to work her wiles on the main character, so that he can give her the full rejection. And the attitude toward the little girl is just creepy, as she is primarily described in terms of her future desirability as a sexual companion. She and the main character (a man in his 30's), get "engaged" just before he goes into suspended animation, and he gives her instructions to also put herself into suspended animation when she's 21 so they can wake up together and get married. Which they both do. And even then, she's treated as though she's still that little girl, only with a sexy adult body. Gross.

Audiobook, borrowed from my public library via Overdrive. The performance by Patrick Lawlor is excellent - he reads with just the right amount of self-aware amusement - and dragged this book back up to 3 stars to redeem it from its miserable female characters. ( )

Creative exploration of engineering, Time Travel and Cold Sleep in Fiction, but marred by patriarchal roles and misogyny as essential parts of societal customs. Typical Heinlein

The cat is the only character I remember, but not the plot. ( )