Insular Norman was, for the most part, the main everyday language of the Channel Islands until the twentieth century. Today, the Norman dialects spoken in Jersey, Guernsey and Sark are all severely endangered. The dialect of Alderney (Auregnais) is extinct and has disappeared with very little trace. This study explores the reason why the Channel Island geographically closest to the Norman mainland was the first to lose its Norman tongue. It considers the sources that can be examined for Auregnais in the nineteenth century, when it was still a living language, in order to determine what linguistic information can be uncovered about this seemingly invisible variety of Insular Norman and attempts to provide an outline of some of the linguistic features of Auregnais set alongside those of other varieties of Norman.