Earth is facing an interstellar invasion that it does not know is coming and for which it can't provide a defense. The Antoran people were able to escape from the invasion since they had adequate warning and an advanced technology to allow it. Antorans were able to travel considerably faster than the invaders so they used that to put some distance between themselves and the invaders. This occurred some 500 years ago but now the invaders are coming toward Earth. The Antorans have the equipment to withstand the invasion but they are incapable of firing defensive or offensive weapons. They can build the equipment but can't use it, so they are looking for someone who can.
The Antorans have had Earth under surveillance for more than 400 years with part of its cloaked (invisible) fleet of spaceship/stations. The spaceship/stations are immense constructs, the prototype is 260 miles long by 60 miles in diameter. Smaller vessels are either 200 miles by 60 miles or 90 miles by 60 miles. They each carry a large fleet of warships.
They have been looking for the right person to command their fleet and lead an effort to counter the coming invasion. They have determined that Henry (Hank) P. Stone is their best candidate and they proceed to recruit him. He must now build and train a force sufficient to man the Antoran ships and do it in time to meet the invasion force expected to arrive in 25 years. The necessary force will require tens of millions of persons so the task at hand is not an easy one.
The Antoran technology is at least a thousand years more advanced than that of Earth but the Earth forces recruited must learn how best to use it. This is substantially supplemented by a growing telepathic capability.
The question becomes, what happens when the technological difference in capability is so divergent that the choice of "kill or be killed" is no longer the only option on the table. Four other civilizations are located within 20 light years of Earth and these too are considered as potential sources of manpower to meet the invaders.
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