We have all seen people step through a doorway and “disappear.” While such events are usually chalked up to an inattentive observer or a clever rogue, the truth is sometimes far stranger. You may have (almost) seen someone step into another plane.

The uncomfortable realm that some sages call Axis Mundi is a powerful place-between-places, accessible from every plane in existence without the benefit of magic. One could quite possibly slip through a doorway in an alley in Viridistan, run down a corridor, and slip through another doorway to land in the midst of a genie noble’s harem. Traveling somewhere is embarrassingly easy. Traveling somewhere specific is the real challenge.

Axis Mundi is known by many names among those who frequent its halls, including: access tunnels (or mockingly, Access Mundi), transplanar conduits, ancients’ passways, the Between, and behind the scenes.

Attunement

To effectively use the secret doors and passages of Axis Mundi, an individual must be attuned to the plane. Typically, this involves an initiation rite where a seasoned traveler takes a potential initiate into the Between, where the initiate spills its blood (or makes a similar offering). More rarely, someone escorted through the conduits — or even someone who has simply studied a frequently-used access point — can eventually learn to see and use these portals.

In game mechanics, Attunement to the Between is a new feat whose only requisite is that the character have traveled through Axis Mundi, or seen an access point used at least 3 times at close range. Without this attunement, any attempts to recognize an access point or navigate the tangled conduits become almost impossibly difficult (as noted below).

Recognizing an access point

Axis Mundi has connection points on every plane of existence. Most of these points are fixed in space, though some cyclical or wandering portals exist. Major earthquakes and similarly dramatic events may shift the location of a fixed access point, or knock it loose. There may also be ways of anchoring a wandering access point. Some gods may even have ways of making new access points.

Frequently-used access points are often incorporated into a building. Indeed, access points will often move a few yards to align with doorways and other points of egress. Such props are not required, though. An access point can just as easily occupy a doorway or window, follow a wandering route thousands of feet in the air, or sit in a lava flow deep beneath the earth.

The world seems to thin slightly at an access point, not unlike walking across a hollow floor compartment. Much like such a compartment, the effect cannot be detected at a distance. An attuned individual can feel the closeness of the Between from an adjacent square, while an uninitiated seeker must touch the access point (and enter the square). The seeker must succeed two skill checks: Search and Knowledge (physical universe), both at DC 40 for the uninitiated, or DC 20 for an attuned individual. These checks must be made every time, even if the location of an access point is known.

If both skill checks succeed, the seeker must make a DC 15 Wisdom check to unseal the access point.

The open door

An open access point is non-magical, and plainly evident to all senses. It looks like a strong heat shimmer, and it feels like the oppressive charge before a storm. It makes short hair stand on end and ears ring. All of these effects, however, are only observable within a few feet of the access point. The heat shimmer can be seen from thirty feet away, and all other effects are only observable in a 10’ radius.

An open access point does not interrupt line of sight or line of effect, nor does it provide cover or concealment, for any parties on the same plane.

Using an access point is an act of will. Unattended objects, liquids, gasses, etc. do not pass through the portal under any circumstances. Creatures of animal and lower intelligence shy away from an open access point, and only use it if compelled or commanded.

Once opened, an access point remains active for one minute unless closed or held open from the other side (see below). Access points opened from the Axis Mundi side stay open a single round before closing.

On the other side of… everything

Axis Mundi is a world of paths. The details of its appearance are subjective, but its reality is constant. The paths may appear natural or manufactured, dark or bright, warm or cold (this subjectivity is not unlike what travelers find in the plane of entropy. Ultimately, the only important distinction is between enclosed and open paths. Open paths provide sight lines and other clues to navigation.

The Between is not a place to spend any length of time. It is a barren land with no native organisms. It has the following planar traits:

• Subjective directional gravity: “Down” is inherited from the plane of origin, but may be changed with a DC 16 Wisdom check as usual.
• Dead magic (including psionics): Spells and psionic powers do not function here, nor do spell-like or supernatural abilities. Any energies expended are wasted. These energies cannot be regained until leaving Axis Mundi.
• Static: The apparent material of Axis Mundi cannot be altered. Swords cannot cut, nor axes pierce, nor fire burn, the material of this plane. There are no native unattended objects that can be pried loose, though objects left by other travelers can be claimed with a DC 14 Strength check.
• Flowing time: Typically, one round of time passes outside for each hour (or fraction thereof) spent traveling the conduits. All transit takes at least one round of external time.

Thankfully, unlike many places with subjective planar traits, the spatial relationships among portals in Axis Mundi are fixed. Conduits may change in apparent dimensions, but “six portals on the left, take the next right, eighth portal on the right” will always lead to the same door.

Travelers plying the ancients’ passageways quickly learn that there is no succor here: no game to hunt, no potable water to collect, and no access to magic to make up for it. Fires are hard to start and burn fitfully, and wounds refuse to heal. Perishable food stays fresh, but this is scant comfort.

While in the Between, travelers are immune from contact or scrying. As long as the journey lasts, all divination magic targeting the subject automatically fails. Those attuned to Axis Mundi can tell when a divination effect fails because the target is in transit.

With an attuned navigator, transit through the tunnels can be strange, uncomfortable, and occasionally overlong, but rarely dangerous. Encounters in the corridors are rare, and even more rarely result in combat. Few travelers would risk getting hurt in a dead magic zone, especially when it’s a place where wounds don’t heal.

Scattered throughout the Between are access points to various planar coordinates. Every 100 feet or so of corridors yields another dormant portal. These access points do not connect to the outside world at random, but accurately mapping their correspondence is exceedingly difficult. Frequent travelers have developed a variety of tricks to facilitate travel: mnemonic devices to remember complex paths, mathematical models to predict the position of a desired portal based on known portals, or even guides who wait in the conduits to find lost souls.

And most travelers at some point do become lost.

Since the plane’s appearance is subjective and distances relative, those traveling more than a few doors down the corridors stand a chance to lose their way. It is, however, a world of doors. Those who get lost can always begin searching for an access point that seems to lead somewhere safe.

Scrutinizing access points

From within Axis Mundi, all access points appear as doorways, blocked by a screen or membrane. At less than 10’ away, travelers can see dimly through the membrane, though time dilation can make it difficult to make sense of events.

Savvy travelers can also study the membrane itself to discern the destination’s planar traits. A Knowledge (the planes) check as a standard action (DC 20) yields one planar trait. If successful, the character can try again to uncover more planar traits.

Stepping back into reality

Opening a portal from within the ancients’ passageways just requires a moment’s concentration and centering (Wisdom check DC 15, which may be retried). The doorway stays open as long as someone maintains physical contact with the Between side of the doorway, and closes one round afterward.