Smith wrote this series over a long time and the order you should read them in is subject to debate. I am taking them in the internal chronology order, which is not the order Smith wrote them in or the order you might have read them back in the day. I have read them in this order multiple times and it always seemed satisfactory to me.

Triplanetary

Smith wrote the novella Triplanetary and had it published in four installments in the January through April issues of Amazing Stories 1934. You can go back and read the original at The Internet Archive. It is a nice story in the style of the time, but at this stage it had no connection to the Lensman series, which didn’t appear until 1937 in Astounding Magazine with the serialization of Galactic Patrol. So incorporating it is a type of retcon, or retroactive continuity.

Atlantis

The book Triplanetary, published in 1948, began with a series of of stories that recapitulate episodes in the breeding program set up by the Arisians. The first section tells the history of the conflict between Arisia and Eddore, which we discussed in the previous page. The first of the stories takes place in Atlantis, where a war is brewing between Atlantis and the nations of Norheim and Uighar. Atomic Energy has been discovered and nations are suspicious of each other. Of course, Eddore is behind this. As relations get bad, an Atlantean agent named Phryges goes on a mission to Norheim, where he meets up with a woman named Kinnexa. And as it happens these two are part of the breeding program that the Arisians have set up. Phryges has gold-flecked, tawny eyes, and a flaming thatch of red-bronze-auburn hair. These descriptors characterize this branch of the breeding program at all times. And the other branch will become known as the Kinnisons, and Kinnexa is an ancestor. Before Phryges leaves for his mission, he makes sure that his wife and baby are sent to another continent for safety. So when he and Kinnexa both die on the mission, there is an infant to carry on the breeding program. And that is what Arisia is doing behind the scene. While Eddore is destroying civilizations, Arisia makes sure the breeding program goes on.

Rome

Next is a similar story, this time set in Rome at the time of Nero. An Eddorian named Gharlane is high up in the Inner Circle of Eddore. He has responsibility for four planets that are giving him headaches because as soon as he destroys their civilizations they seem to bounce back. And of course the four planets are Tellus, Velantia III, Rigel IV, and Palain VII. And the reason they bounce back is that the Arisians are guarding their breeding programs. Back on Tellus a gladiator named Patroclus has gold-flecked tawny eyes and a shock of red-bronze-auburn hair. He and other gladiators have conspired to kill Nero, but what they don’t know is that Gharlane is actually Nero, or more precisely Nero is a bundle of flesh energized by Gharlane. Then again, some of the gladiators are energized by Arisians. So needless to say, Patroclus is not allowed to succeed. The Arisians regret letting Nero continue but it is necessary to give their breeding program more time. Nero will do his best to screw up the Roman Empire.

World War I

An aviator named Ralph Kinnison is a Captain, and he gets shot down. He is fortunate, though, to come down near soldiers on his side. Then he has to make it back to his unit, but along the way he is seriously wounded. fortunately for him, he does survive, but his war is over now.

World War II

Ralph Kinnison did survive, he got married, and now has an adult son when the Japanese bomb Pearl Harbor. His son is an Aeronautical Engineer, so he won’t be going anywhere. But Ralph wants to do something, and Army won’t take a 51 year old. But he finds a position at an explosives plant as a chemical engineer. Her is really good at it, and rises to a management level. But in the end there is a conflict because some of the parts they are working with are substandard. He ultimately gets fired in a conflict with upper management, but he has shown himself to be brave and uncorruptible. This story is pretty realistic because it draws on Smith’s own experience. For his Ph.D. at George Washington University he studied under Doctor Charles E. Munroe, who he described as “probably the greatest high-explosives man yet to live”. 

World War III

Theodore K. Kinnison is married and has two children, a boy and a girl. When he gets a signal that missiles are coming over the pole, he puts his wife and kinds into a car and has them hot-foot it to visit his father out in the boonies. Then he gets going to to man his combat rocket. His mission is to shoot down as many missiles as possible, but finally one missile gets past him and explodes, killing him instantly. Good thing his wife and children got away. And Gharlane of Eddore goes away, confident that he has destroyed the civilization of Tellus for a long time. He then moves on to Velantia III, Rigel IV, and Palain VII, do do similar things to them. But the Arisians decide that the breeding program is close enough to being done that they can begin to take a more open role in opposing Eddore. They place a Zone of Compulsion on Gharlane, and he won’t realize it until it is too late.

Triplanetary

With the hidden help of the Arisians, the civilization on Tellus has managed to clean up the radiation from World War III and rebuild. They have started to expand into the Solar System. They have met the inhabitants of Venus and Mars, and at some point previous to this story fought a war against the Adepts of the North Pole of Jupiter. Now there is a piracy problem, and an agent of the Triplanetary Service is aboard as the First Officer. He is Conway Costigan, and while dancing with a young lady named Clio Marsden he detects V-2 gas, mere possession of which is a death penalty. It knocks out most of them, but Costigan was able to warn the Bridge so the Captain is OK. This turns out to be the work of pirates led by Gray Roger, we appears to be an Adept from the North Pole of Jupiter. But in fact he is Gharlane of Eddore, back to continue his work on Tellus. He is still greatly puzzled by what he finds. Tellus should have been down for millenia after World War III, but here they are exploring the Solar System. So in due course Captain Bradley, Conway Costigan, and Clio Marsden are captured and brought on board Gray Roger’s space station. He has a crew of criminal low lifes and misfits, and the three are locked up.

The ships of Triplanetary are trying to find out what is happening when the head of the Triplanetary Service, Virgil Samms, sends out a message to a number of undercover operatives to reveal themselves to their commanding officers and implement measures. And while we are on Virgil Samms, it is worth remarking on the fact that he has gold-flecked tawny eyes and red-bronze-auburn hair. Gray Roger’s Space Station has been located, and the fleet is headed these. But Samms want one ship, carrying one of his top scientists, to stay back and take pictures, which is a good thing because the fleet battle is very close. Apparently Gray Roger is a lot more powerful than anyone expected. But then another player joins the game.

A ship from the planet Nevia arrivers having scoured space for a source of iron, which is very rare on their home planet. And in this battle there just tons of the stuff, which they collect with a ray that turns the iron into a liquid which they suck into their tanks. Nevia is a water world, and the Nevians are aquatic. And as they are sucking up the iron, a lifeboat with Captain Bradley, Conway Costigan, and Clio Marsden gets picked up, and the three are brought back to Nevia to be studied by their scientists. From here we have an extended sequence of the three Tellurians trying to escape, and the Nevians thinking they are sort of intelligent, but not by much. Meanwhile, back on Tellus, the Arisians energize a form of flesh called Bergenholm, who develops something called the Inertialess Drive. This is Smith’s answer to Einstein. He says that it is inertia that keeps things from going fast, and that if you can neutralize the inertia you can go much faster than light. This is helpful since a ship with this new drive can take off after three captives from Nevia who have managed yet another escape and are on route home while being chased by the Nevians. A little more fighting happens, and then The Nevians and the Tellurians realize they ought to be friends instead of enemies. . So despite Gharlane’s efforts, the Tellurians have now started to expand beyond the Solar System. Which of course is all part of the Arisian’s plan. They picked Nevia to intervene at exactly this time.

This is a good book that sets up the conflict between Arisia and Eddore and leads us into the rest of the series