Galactic Patrol by E.E. Smith

Dominating twice a hundred square miles of campus, parade ground, airport, and space port, a ninety-story edifice of chromium and glass sparkled dazzlingly in the bright sunlight of a June morning. This monumental pile was Wentworth Hall, in which the Tellurian candidates for the Lens of the Galactic Patrol live and move and have their being. One wing of its topmost floor seethed with tense activity, for that wing was the habitat of the lordly five-year men, this was graduation day, and in a few minutes Class 5 was due to report in Room A.

Room A, the private office of the commandant himself; the dreadful lair into which an undergraduate was summoned only to disappear from the Hall and from the cadet corps; the portentous chamber into which each year the handful of graduates marched and from which they emerged, each man in some subtle fashion changed.