While James White is best known for the Sector General series, he has written many more science fiction novels. This is one of his best, easily equal to any of the Sector general series. The book is set in a near future after humanity’s contact with aliens. The aliens offer to relocate all of mankind who qualifies to the Federation World, a Dyson sphere near the center of the galaxy. The principal characters are not accepted for citizenship, instead qualifying for positions on the Federation staff. Their job is to make contact with new species and to invite them to join the Federation if they qualify. White’s writing is remarkably clear and easy to read