E. E. "Doc" Smith’s novel Triplanetary was initially published in serial form in Astounding Stories in 1934. Smith later extensively reworked the novel to serve as the first of two prequels to his Lensman series. The reworked version was published in book form in 1948.
Triplanetary tells the initial part of the aeons-long struggle between two highly advanced civilisations, the Arisians and the Eddorians. The Arisians are very much the good guys while the Eddorians are equally emphatically the bad guys. The Eddorians, to all practical purposes immortal and formless, have the ability to take on many corporeal forms.
The Arisians are aware of the uncomfortable fact that they cannot defeat the Eddorians. They can however direct the evolution of other life-forms that will eventually (if the Arisians’ long-term plans work out) be able to stop the Eddorians.
Humans are the species chosen for the Arisians’ long-range eugenics program. The first half of the novel takes us first to ancient Rome and then to the three great 20th century world wars. A gladiator is the instrument chosen to destroy the emperor Nero, who is in fact an Eddorian whose mission is to destroy Roman civilisation. In the world wars various members of the Kinnison family play a key role. The Kinnisons are one of the blood-lines destined to be the instrument for a final war against the Eddorians.
Human civilisation is all but destroyed but is rebuilt by the Arisians. Human civilisation spreads throughout the solar system in the Triplanetary League.
The second half of the novel is the saga of an epic struggle between the Triplanetary League and space pirates led by a man called Roger. Like Nero Roger is an Eddorian in human (or at least humanoid) form. The struggle becomes a three-way conflict when another advanced civilisation, that of the Nevians, intervenes. The Nevians are distinctly non-humanoid amphibians. Their spaceships and weapons rely for their awesome power on a very rare element indeed, iron. The Nevians’ discovery that iron is plentiful on Earth, plentiful to an extent beyond their wildest imaginings, will prove to be of crucial importance directly to the Nevians, and indirectly to human civilisation.
Triplanetary’s second half is pure space opera, albeit space opera of a fabulously inventive kind. Triplanetary secret agent Conway Costigan is a classic square-jawed space opera hero of the Flash Gordon type that became so popular in the 1930s. Smith is very adept at describing epic space battles and is equally skilled in the imagining of strange alien worlds such as the aquatic world of the Nevians. The submarine battles on Nevia are as spectacular as the space battles between the Triplanetary League and the pirates.
The Nevians prove to be formidable adversaries but they are not conventional villains. Their actions make perfect sense from their point of view and Costigan and his fellow adventurers, captured by these amphibian space roamers, develop a grudging respect for them. While the Eddorians are pure evil the Nevians are simply alien, pursuing their own interests as they understand them. The Nevians regard humans with fascinated repugnance but as the story progresses the fascination comes to outweigh the repugnance.
The discovery that iron can be an immensely powerful fuel source allows the Triplanetary League to complete a super spaceship named the Boise. The Boise allows humans to achieve faster-than-light travel and to expand their horizons far beyond the solar system.
Smith’s style is rather pulpy but it’s wonderfully energetic. The scope of his imagination is dazzling and puts the novel in a different league from the Flash Gordon brand of space opera. Triplanetary’s story spans not merely centuries but billions of years. To the Arisians and the Eddorians the span of a human life is so brief as to be inconsequential.
Triplanetary offers excitement combined with ideas on the grand scale and you can’t ask for much more from science fiction. Highly recommended.