Larry Niven's Protector is a book about an ancient race of aliens, the Pak. The eldest of these aliens become protectors. A protector's only purpose in life is to take care of the offspring of the race. With no offspring left on the home planet after centuries of war, this particular protector (called Phssthpok) has to take off and space travel in search of some offspring that left millions of years before, or stay behind and die. What he finds is Earth and its colonies.
The idea behind the plot is fascinating. Humans have colonised other planets? The ones left on Earth live peacefully, unknowing that there is a warmongering alien flying towards them? Tell me more about it! Unfortunately it feels like the story plays second fiddle to the space travel physics. It was more science than fiction (and I can't vouch for the accuracy of the science, either). This becomes evident in the frequent time jumps in the story. We often flash-forward days, years, centuries, and the characters that we knew are suddenly replaced by new ones.
This book had its moments. Among the descriptions of space battles and confusing explanations of how ramrobots work, there were little pearls of plot or glimpses of a character's back story or personality. Those were too few and far between, though, and most of the time I hadn't gotten to know a character enough to care about what happened to them. I couldn't understand what motivated them to make their decisions, some of which seemed outright illogical. Because of that, the book felt dry and I never got emotionally involved.
It was a quick read despite everything. What might have elevated it from ”meh” to ”good” for me would have been a stronger, more detailed plot and better developed characters.