That old master of SF, Robert Heinlein, knows [science fiction] well enough to make fun of it. Kip, his engaging hero [in Have Space Suit—Will Travel], saves the world from an invasion of bug-eyed monsters—or their equivalent—and then goes back to his part-time job as soda-jerk in a drugstore. Kip has a nice line in wise-cracking: he also has great courage and deep humanity—it is his humanity which responds to the wisdom and tenderness of the Mother Thing. The M.T. is a Vegan, small, graceful and feline, and above all comforting…. As the complex, powerful story develops, the M.T. changes and becomes infinitely more formidable, but her vast compassion grows proportionately and she becomes no less lovable.

A few other writers manage the science in SF almost as well as Mr. Heinlein; no one else has his lightness of touch, the gaiety...