In 1963, Charles Melman was the first to describe a clinical feature specific to certain hallucinatory persecutory delusions which he called the party wall phenomenon. In this phenomenon, the intimate contact between the persecuted and the persecutor is established on either side of a party wall. This feature, which Melman so brilliantly isolated, seems to us to have the potential to shed light on entire sections of the psychosis clinic, which we revisit with the help of Lacan’s ingenious commentary of De Clérambault’s mental automatism concept.