Nowadays, Hector Malot is mainly known for his books for children. However, that was not what made him famous in the 19th century, a time when he was much more notorious for Un beau-frère (A stepbrother). In this novel, first published in 1868, Malot gave a dreadful depiction of the French asylum system. It was a great success and the controversy was such that from this time on Malot was considered as a defender of the insane. Malot was thus the first “anti-alienist” author of his time, and he created a new kind of literary “genre”, which I called “asylum novels”. He was also the first writer to be seen as an “amateur psychiatrist” : people would come to consult him, ask him to examine their mental state or request that he visited a confined relative. By studying this forgotten aspect of Malot’s work and life, this article aims to shed light on the “anti-alienist” culture of the fin de siècle, a time when people wonder who was the most dangerous, the mad or their psychiatrists.