And the Heinlein riff keeps moving right along. Except this time, it's a novel that explicitly credits Heinlein in its acknowledgments. John Scalzi's novel of humans at war in space looks back to Starship Troopers as its inspiration, and there are many similarities. But there are enough differences that allow Old Man's War to stand out from its sources with its own identity.
What separates Old Man's War from the prodigious stack of military speculative fiction is the technological conceit it turns on—citizens register to join the armed forces at age 75 with the promise of a revitalization process that will make them feel young again. Of course, what they get is far more radical than y of the signees can imagine, and the novel does a good job of building up the tension to the big reveal. The main character, John Perry, narrates throughout the novel, so our point-of-view is not remotely omniscient. Perry is a fine human narrator with faults all his own (for instance, he isn't nearly so funny as he thinks he is) whose humanity becomes vitally important as the plot moves on. Because Scalzi also creates some wonderful alien races, employing only a few clichés and more noticeably relying on the idea that we may never understand the motivations or actions of an alien race (the lecture that the recruits receive on this very fact is entertaining enough but foreshadows future events very nicely). Too often, aliens in simplistic SF are like the bugs in Heinlein's Starship Troopers, with motivations and processes that are easy for humans to relate to. Scalzi's aliens are like the Skinnies in Troopers, with motivations that we may be able to perceive the edges of but who humans truly never know. While this is most likely what we would find if we travel ever do find aliens, it is a difficult subject to write about, not the least of which because it is difficult to make the unknowable entertaining.
And entertaining is what this book ultimately is, a coming of age story with a 75 year-old protagonist. Perry discovers that the military isn't just revitalizing his body, they are providing him with an entirely new one based on his own DNA profile but modified for military specifications. Scalzi, through Perry, briefly explores what this fundamental change in condition means, and by itself it has been the foundation for longer deeper treatments. But Scalzi also uses these training moments to fully introduce the setting of his story—the universe that humans find themselves in and the method by which they are governed, mirroring the lectures in Starship Troopers. However, Scalzi doesn't lecture so much as have his characters reminisce; after all, the novel doesn't suggest a completely alternative governmental system as does Starship Troopers. But there is the interesting twist that the Colonial Defense Forces, the agency responsible for colonizing and defending those colonies, holds a monopoly on space exploration, and the reader is given a perspective from within that monopoly about why such a set-up is optimal.
After his training, Perry is sent off to battle humanity's foes, and the action is relatively straightforward, though somewhat light on the details of the battles. Scalzi lets the imagination of the reader provide the details as he generally paints battles with a broad stroke. After all, the battles are not really what this novel is about; instead it is about the effect of the new technology on the characters and their relationships with others, including aliens. And along the way, John thinks that he sees his dead wife in service, opening the door to a delightful (for the reader, a lot of other things to the characters) extrapolation of the technology that the story is about. Instead of remaining a war set in space, Scalzi opens wide the narrative opportunities with a supple twist, one which promises many more thought-provoking books down the line.
As a result, Scalzi skillfully dances along a narrative high wire, appealing to the relative simplistic battle fiction with an action yarn about fighting aliens while developing a fascinating technology that, at its core, reflects the very best that science fiction offers. And while the clichés of the former remain (Perry becomes a battle-decorated hero by the end of the novel), the underlying tensions are far greater than the clichés. Old Man's War is a delightful, smart and quick read, a very promising introduction to a new universe for which three other books have already been written.