Schaller, an interpreter and teacher of American Sign Language (ASL), tells the extraordinary story of a deaf Mexican man who learns his first language at the age of 27. In some ways, this reads like a book-length version of one of Oliver Sacks's case-studies of psychological breakthrough (and indeed, Sacks provides a foreword here). The story is simple: Schaller takes a job in a program to aid the deaf and soon encounters "Idlefonso," a 27-year-old deaf Mexican rocking silently in a comer of her classroom. After a week of face-to-face work, Schaller transmits to him the idea of language: "The whites of his eyes expanded as if in terror. . .He had entered the universe of humanity, discovered the communion of minds." After the breakthrough come months of painstaking progress, culminating in a reunion between teacher and pupil after seven years absence--Idlefonso is now an animated, articulate speaker of sign language. Schaller also recalls past efforts to deal with languageless people (Kaspar Hauser, Ishi, wolf children), and raps the academic establishment for sloppy scholarship on language acquisition--above all, for the cherished but misguided notion that language can only be learned in childhood. Beautifully written, with a nimble interweaving of personal anecdote and historical background. This sits well alongside other classic studies on the culture of the deaf, including Sacks's own Seeing Voices.