This note contains spoilers for the book.

A pair of old classics, and they've apparently been packaged together like this since 1950.

Waldo suffers from myasthenia gravis, and being a genius (starting as a child). So he's kinda unsocialized, but quite rich, and lives in a space station. He invented the "waldo", a teleoperated hand, for his own convenience, and also finds it lets him do precision machining on Earth, and train other people. He's weak, but he's learned to be terribly precise (perhaps from practicing with waldos that amplify his power?). Note that this term is somewhat used in the real world.

But then things get weird. The wireless power transmission that runs cars starts failing, and when the scientists of the power company fail, they scheme to get Waldo involved. He gets involved, and gets shown by a Pennsylvania dutch (which is really German) hex doctor how to teach the power system to reach out and get power from another dimension. This is all tied in to the suggestion that the power flowing through everybody is causing illness, including Waldo's. So he sells a solution to the company that ends up giving everybody free power, and he learns to tap it himself and becomes strong. In a flash-forward, we see him completing a "ballet tap-dance" performance, and then I think running off to a hospital to operate on somebody—a clear precursor to Buckaroo Banzai.

Meanwhile, in Magic, Inc., science is a sideline, because magic worked, and got investigated and systematized. And there's a new guild moving into town, using unsavory practices to try to corner the market in magicians. Turns out to be demonic, and of course in the end it's defeated.

Poul Anderson's much later Operation Chaos clearly borrows from the basic concept of magic as the normal way of getting things done (and acknowledges it in the introduction).