The Frontier Rebellion has long been won, in large part thanks to the efforts of Culihan O'Rourke When, the best hijacker the Rebels ever had. So why is Cully lured to Earth on a pretense by the sweetheart of his youth, then 'welcomed'with beatings, interrogation and torture? Because, Cully learns, the Moldaug aliens, after peacefully coexisting with Earth since First Contact over 50 years ago, have given Earth an ultimatum: Evacuate the Frontier or see Earth become a cinder. The Terrans think that it's an Outposter Plot, and as a war hero and potential leader, Cully's going to take the heat. But Cully is never one to take things lying down, and he makes up his mind to wage his own war--and when he makes up his mind to do, he does---no matter what the odds.
The book also has the prologue story introducing Cully When, the original Outposter.
The movie, Outposter, was loosely based on this book.
It is not part of Dickson's Childe cycle.
Good adventure space opera.