This is one of Heinlein's "juveniles"--books written for and about teen boys. In this one Kip Russell is trying out a space suit in his back yard when a flying saucer lands--and he gets kidnapped. I like Kip, Peewee, the eleven year old girl genius, and the "Mother Thing" alien they encounter in their adventures. Despite it's inclusion by David Pringle in his list of 100 Best Science Fiction Novels, not one of Heinlein's more remarkable tales. It doesn't have one of the more imaginative premise featured in his books and doesn't heft any philosophical weight like his adult novels. I do find amusing the parallels between the tribunal at the end of the book and Q's trial of humanity in the Star Trek: The Next Generation pilot though. This is basically a fun romp, an entertaining and very readable book.