Dream work constitutes the interval phases of the diphasic organization of mental functioning according to the process of après-coup. This article explores the implications and aims of the sleep/dream system: the attempt to fulfil a wish hallucinatorily; the guardian of sleep; the temporary denial of perceptions of lack; the anti-traumatic function of restraint due to saturation; cultivation of the retrogressive path and the registration of memory (the time machine); the libidinal regeneration of cathexes (bath of rejuvenation); the protection of the soma by limiting sensual regression; the orientation of sexual cathexes towards the mind, the body and objects (the light of dreams); awakening, and the links between oneiric and erotic life. Under the aegis of the imperative of registration, the sleep/dream system uses the extinctive regressivity of the drives in the service of sexual, narcissistic and object cathexes, bonuses of desire.