Children of Tomorrow is a 1970 novel

Novel

A novel is a book of long narrative in literary prose. The genre has historical roots both in the fields of the medieval and early modern romance and in the tradition of the novella. The latter supplied the present generic term in the late 18th century....

 by American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 author A. E. van Vogt

A. E. van Vogt

Alfred Elton van Vogt was a Canadian-born science fiction author regarded by some as one of the most popular and complex science fiction writers of the mid-twentieth century: the "Golden Age" of the genre....

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Plot introduction

Commander John Lane returns from a ten year mission in space

Space

Space is the boundless, three-dimensional extent in which objects and events occur and have relative position and direction. Physical space is often conceived in three linear dimensions, although modern physicists usually consider it, with time, to be part of a boundless four-dimensional continuum...

to find that the teenagers of Spaceport City have organized
themselves into "outfits", well disciplined, non-violent little gangs with their own customs and argot, and that the parent's
role in teen upbringing has become minimal. His 16 year old
daughter Susan belongs to the Red Cat Outfit, whose newest member
Bud is actually a spy

SPY

SPY is a three-letter acronym that may refer to:* SPY , ticker symbol for Standard & Poor's Depositary Receipts* SPY , a satirical monthly, trademarked all-caps* SPY , airport code for San Pédro, Côte d'Ivoire...

for the alien fleet that has secretly followed John Lane as he returned to Earth.