Isaac Asimov The Currents of Space (1952)
Having been told I'd read all of Asimov's top shelfers, so to speak, I promised I would never again subject myself to another puzzle box narrative wherein some lady scientist with a face like a camel's arse exclaims Sizzling Saturn! and strives to keep her womanly but Einsteinian mind free of those despairing thoughts of how no man will ever ask her to be his wife by figuring out why the robots have downed their tools and taken up ping-pong instead; but this was just sat there looking at me from the shelf in Half-Price Books and I couldn't resist.
The Currents of Space turns out to be part of Asimov's Galactic Empire series, conspicuously occupying the same universe as Foundation, which I didn't enjoy at all. That said, aside from the presence of an archetypal Asimov female - obliged by cruel society to develop her intellect by virtue of being a bit of a double bagger - and the closing chapters clogged up with the usual conversation about all that has happened thus far, it's pretty reasonable for the most part.
I'm probably being a bit harsh in regard to Asimov's slightly odd depiction of females given that he was Germaine Greer by 1950s standards; and this chugs along nicely for most of the story, presenting a well constructed mystery and some interesting medium-sized ideas. It's also a reminder of how Asimov was at his best an impressive communicator with a style that, if lacking poetry, never fails to draw the reader in. The Currents of Space may not quite be up there with The End of Eternity or The Gods Themselves, but is not lacking in a charm of its own.