Most human subjugates are young,” said Will. “Vampires like to acquire their subjugates when they’re youthful—prettier to look at, and less chance of diseased blood. And they’ll live a bit longer, though not much.” He looked pleased with himself. “Most of the rest of the Enclave wouldn’t be able to pass convincingly as a handsome young human subjugate—” “Because the rest of us all are hideous, are we?” Jem inquired, looking amused.
Cassandra Clare (2013). “The Infernal Devices: Clockwork Angel; Clockwork Prince; Clockwork Princess”, p.179, Simon and Schuster