This is a nice little a palate cleanser after a series of long and intricate adult novels. It’s short and concise, tightly plotted and narrowly focused, but in a good way. As middle-grade books go, it’s solid.
What’s interesting about it is that the co-author, Michael Gilbert, was (is?) an artist. The illustrations are his. Mostly they’re fairly timeless, though young Hal’s father has a classic Seventies mustache, which is appropriate enough for a book published in 1975. There’s no way he could have known that 2021 would call it a “porn ’stache” and see a distinct resemblance to Freddie Mercury.
The story is set sometime after 1975. Lasers are a fully developed form of weaponry, and there are flying cars. Flying cars were The Future in 1975. Instead we have supercomputers in our pockets. I suppose it’s a worthy tradeoff.