The 24th Aethyr, NIA is the Aethyr of time and space, and it is here you learn how to move your subtle body through it. NIA is the highest of the lower Aethyrs. Mastery of NIA and the lower Aethyrs is the primary qualification of the magical grade of Philolophus. Its mastery is the first step toward the rank of the Magical Dragon (DEO). Philolophus is an achievement that separates the Novice from the Adept. You will undoubtedly be taken on a journey in this Aethyr. Every place you go is a universe in itself. The ease at which you jump from one universe to the next is meant to free you from the confines of physical time and space. Places are not separated by distance and the clock, but rather by the fine graduations of energy and of the mind.
The guide on these journeys is a lovely female or similarly attractive being. Sometimes you will smell her sweet alluring perfume. She is Venus or at the very least a representative of the Venetian order. Ultimately Venus is an aspect of BABYLON, who welcomes you like a returning lover, luring you upward to the Aethyrs beyond NIA. Venus will teach you the lesson of joyful play and oneness of being -- a taste of what is to come in the higher Aethyrs. Acceptance of this joy and of the fact that many of the energies in the upper Aethyrs are of a attractive nature is necessary if you are to go beyond NIA and transverse the Ring-Pass-Not that is above it.
The initiation here is the conquering of your lower natures (uncontrolled emotions, passions, and instincts) in order to experience a higher nature (the lower forms all calmly subdued by the mental or the mind). You see! In the higher Aethyrs, the mind is the director of experience. It chooses what to experience, what not to, when, and how. In the lower state, the mind has no control over emotions, feelings, and instincts; it is its servant. However the lower natures are the the servers of the mind, and it is that order of things that you must restore in yourself before you can go on in your evolution or on to the other Aethyrs. Venus makes this idea worthwhile and she entices you to discard your lustful wandering notions for something more fulfilling: the merging with the divine spirit and the unlimited possibilities that open up, once the mind is free to direct the individual where in time and space it will experience that which it chooses.
* additional source material: "Enochian Magick" by Gerald J. Schueler, "The Golden Dawn" by Israel Regardie