Separating Tariel from the Dark Beyond is what is most commonly referred to as the Divide; a protective planar field that expands in what scholars believe to be a protective, magical shell. It was created long ago by the gods to prevent beings from the mortal realm in reaching the High Halls, and anything beyond. Likewise, it functions as a barrier to keep anything out. Though, given its long existence and slowly dwindling power, there are a few cases where Otherworlders have managed to breach the Divide's magical barrier, and thus find their way into the realm of Tariel. Worlds within the Divide are known as the Planeworlds.
What further separates Tariel from the Planeworlds is what is known as the Veil. The Veil is part of the Divide, though is considerably weaker than the overall power of the Divide's barrier. The Veil's weakened state has caused many Planeborn to be able to reach Tariel, and the other way around as well. Compared to the Divide and Tariel itself, the Veil holds the largest concentration of magical energies. It is believed that this particular part of the Divide was created to soak up any inbound and outbound energies, to further maintain the magical balance of the local universe.
Mages, through long studies, have found ways to create personal sanctuaries within the Veil; though this is a feat only the most powerful mages can master. As the Divide is built up mostly by magic, mages find great interest in unraveling its secrets. There are plausible theories that the Divide is where all the world's magic gathers before being released back into the mortal realm. As a landscape, the Divide appears as shattered and barren, with lost spirits and magical monstrosities wandering the floating isles. Magical energy presents itself visibly as sparks and mists, and the skies that surround the Divide consist mostly of distant, bright stars. Ruined structures from the time when the Starborn occupied the Divide still remain there, as remnants of an ancient civilization.
Both the Divide and the Veil have been described as the After-Realm; partly because, in most Faiths, it is known that the spirits of the dead are attracted to the Divide and the Veil; though a majority of deathly spirits end up wandering the expanses of the Veil over the remaining Divide. It is there that these spirits wander the stars and vast mists, sometimes for entire ages, until a deity willing to take them in collects them to become subjects of their Halls. But only those deserving of such privileges are said to be accepted, whilst the rest are either claimed by Kelmora, the Goddess of Death, or by Melissandra, Goddess of the Faithless. Kelmora takes them back to her realm, the Fade, whilst Melissandra takes the fouler, sinful souls with her to the Eternal Hells.
The Divide and the Veil aren't only traversed by spirits and souls, but also by demons, celestials, planewalkers and many other creatures and beings. The Divide is by no means considered a safe haven, even for souls, as there are plenty of dangers there that seek to cause harm to any who crosses their paths. Many deities forbid attempts at traveling to the Divide and the Veil, and many scholars advise against any magical experiments involving the Divide.