This note contains spoilers for the book.

A weird physics story, and a rare Heinlein fantasy, packaged together as they always have been.

Waldo is a consulting engineer, and a genius. He lives on Freehold, a satellite home (unique), which he does not like having called Wheelchair. He suffers from acute myesthenia gravis, and hence is terribly weak.

The technology for sending power wirelessly, including to moving vehicles, is starting to fail too often. The engineers for the power company are at a loss, and they're terribly scared—the truck crashes are tolerable, but what if such a power failure hits a city? (Their cities seem to be built much more underground than ours.)

And Doc Grimes, Waldo's only real human acquaintance (he does business with people, but doesn't much socialize with anybody but Grimes, who has been his doctor since childhood and dares to be rude to him) thinks that all the power flowing through the air is making people sick. Kind of an echo of the paranoia about high-tension lines, and a pre-echo of the paranoia about cell-phone signals.

A hex doctor shows them how to get the de kalb receptors to reach out for power into the Other World, and then they don't have to transmit power at all any more. Nobody questions whether anything in the other world might be disturbed by this; Doc Smith investigated that in Subspace Encounter (#2) and Asimov in The Gods Themselves.

He also teaches Waldo to be strong. Waldo then takes up a career as a "ballet tap" dancer. The story is framed with Waldo performing, and having to rush from the performance to perform an operation (now that he's strong, he still has all the ultra-fine control he learned while weak). This seems to me to be so exactly echoed in Buckaroo Banzai that I can't believe it's a coincidence.

The term "Waldo" is used to describe remotely operated manipulators, especially those mimicing the human hand. In the story, Waldo invents them.

"Magic, Inc." investigates magic-as-technology. In this world, magic got repeatable and teachable before science did, so it's the big deal, and there are just a few people playing with science around the edges. The plot of the story is largely about criminal conspiracies to achieve monopoly pricing in magic.