“Every once in a while Nature gives us insight into the human condition by providing us with a unique case whose special properties illumine the species as a whole. Christopher is such an example.”Christopher has a startling talent for language learning, thrown into sharper relief by his concurrent disabilities. Autistic, apraxic, visuo-spatially impaired, and with a severely low non-verbal IQ, he has been feeding his linguistic fascination by collecting languages and has now mastered more than twenty. Neil Smith and his colleagues have been working with Christopher for over twenty years, and The Signs of a Savant: Language Against the Odds (Cambridge University Press, 2011) is their second to detail their work and Christopher’s progress, following on from The Mind of a Savant, published in 1995.The book documents Christopher’s experiences of learning British Sign Language. Like other languages, BSL has a full grammatical system on which its vocabulary hangs, but unlike spoken languages, it relies on physical coordination, and the integration of handshapes, arm movements, body postures and facial expressions, all of which pose problems for Christopher.The results of Christopher’s BSL lessons are analyzed in detail, and the book culminates in a new insights into the nature of the mind and where language fits within the complex system of human cognition.I talk with Neil Smith about savantism, about sign language and about the mind. He also tells me about his first (accidental) steps in linguistics, how they took him to Africa and back to London, and how he is the only author not only to have published a case study on his own son’s acquisition of languages, but also his grandson’s.