This is book 12 of the "Rick Brant" series.

This note contains spoilers for the book.

This is the only one of the Rick Brant science-adventure books I actually had as a teenager. I believe we picked it up the summer we were in Richmond, which may explain why I didn't see them in Minnesota. Though I see no reason why they should have been more popular in the south; they had no particular southern slant that I can find.

This is the origin of their radio system—though the legality of it doesn't match my understanding, but I'm not a ham now, let alone then, so I probably just have the rules wrong.

The title is stupid, and the small attempt to justify it inside the book is unsuccessful. The device doesn't "read minds" in any ordinary sense. That phrase has a long history, and it means something totally different from what's meant here. In fact, the reading part isn't important anyway. It's the transmitting the pattern back later, which apparently causes confusion. I'm doubtful.

At least the confusion is short-lived, so retroactively all the jeopardy in the book is somewhat devalued.

This time the author lets the girls go off and try something. But they screw it up (they don't just get unlucky, they're unprepared and careless) and nearly get zombified like the scientists. So no extra points for empowering female characters, I don't think.