I've always joked that Robert Heinlein was better at writing the first half of a science fiction novel than just about anyone. Usually the second half is where he would abondon the high adventure space thriller in favor of his peculiar grand narrative.
Double Star, is just that first half. This breezy 250 page narrative about an out-of-work actor who plays a double for a kidnapped intergalactic politician won Heinlein his first Hugo award.