This is an interesting excursion into hard science-fiction from an
author whose usual output is quite a bit more rollicking. Twenty years
before the main action, Earth was conquered by an alien race called the
Jao. The battle was quite fierce, and pockets of resistance still linger.
The bulk of mankind, however, has been forced to labor for the Jao; the
stated goal is to produce weapons so that Earth may defend herself against
the even more alien Ekhat. No one knows quite what the Ekhat think or
what their goals are, but according to the Jao they don’t like company; periodically
they sweep through the galaxy sterilizing any planet they find that
harbors life. That’s the Jao’s story.

For their part, the humans tend to doubt it. They find the Jao to be
bloodthirsty, ruthless, arrogant, and willing to squish humans like bugs;
and most of them suspect the Ekhat to be a boogeyman conjured up for
propaganda purposes.

The Jao, on the other hand, find the humans to be unruly, unpredictable,
and far too unwilling to be of use–being of use is the first moral
principle among the Jao. And surprisingly, everything they have said
about Ekhat is true, for the Jao are not given to prevarication. They
do not understand humans, and they especially do not understand why
humans are not willing to work harder. For the Ekhat are coming, and
if the humans do not do as they are told, there will no hope of saving the
planet.

In short, there is great distrust, hatred, and resentment on both
sides–and into this stew is dropped a new official, the leading youngster
of his clan, a clan that has generally been at odds with the clan that
administers Earth for the Jao. Conflict is inevitable…but will the
new official be able to turn things around, or will he be destroyed?

It’s an interesting book, as I say, and I quite enjoyed it. The Jao
are actually rather different than they first appear or than the humans
think them; and the reasons for the discrepancy are fascinating. I won’t
go into details, as the reasons emerge over the course of the book and
I hate to spoil the surprises. But it was a reasonably tasty treat, and
a pretty-good page-turner as well.