Every once in a while, a legislature or president or dictator decides to ban CDF recruiting until it reveals its secrets. The CDF never argues; it packs up and goes. Then all the seventy-five-year-olds in that country take long international vacations from which they never return. The CDF offers no explanations, no rationales, no clues. If you want to find out how they make people young again, you have to sign up.

I signed.

"Paragraph five: I understand that by volunteering for the Colonial Defense Forces, I am terminating my citizenship in my national political entity, in this case the United States of America, and also the Residential Franchise that allows me to reside on the planet Earth. I understand that my citizenship will henceforth be transferred generally to the Colonial Union and specifically to the Colonial Defense Forces. I further recognize and understand that by terminating my local citizenship and planetary Residential Franchise, I am barred from subsequent return to Earth and, upon completion of my term of service within the Colonial Defense Forces, will be relocated to whatsoever colony I am allotted by the Colonial Union and/or the Colonial Defense Forces."

More simply put: You can't go home again. This is part and parcel of the Quarantine Laws, which were imposed by the Colonial Union and the CDF, officially at least, to protect Earth from any more xenobiological disasters like The Crimp. Folks on the Earth were all for it at the time. Funny how insular a planet will become when a third of its male population permanently loses its fertility within the space of a year. People here are less enthused about it now—they've gotten bored with Earth and want to see the rest of the universe, and they've forgotten all about childless Great Uncle Walt. But the CU and CDF are the only ones with spaceships that have the skip drives that make interstellar travel possible. So there it is.