The River Oceanus burrows through the walls of reality like a sleeper falling into a dream. How does this appear to an observer?

An outside observer, sitting on the south bank on the plane of Elysium, would see the river coursing by. It moves around a hill and... doesn't come out the other side. Maybe it's a narrow strait, impenetrable woods, or winding through a mountain pass.

If our observer walks around the hill, she shifts with the river. The landscape slowly shifts and changes until it matches that of the Beastlands. With each step, the Elysium night brightens into eternal noon. Animals start crawling around, singing and shouting at each other.

What if our observer is in the air? A flying onlooker wouldn't see the river at all, unless he was right above it. In that case, he would see both planes at once, and would move across them as the river did.

The river Styx is the same way, except it's under no obligation to appear natural. The Styx has plenty of caves, canyons, and tunnels it can duck into to camoflague its planeshifting, but it could just as easily end suddenly in midair. Blind, forgetful Styxfish poke their heads out confusedly before being channeled from the Gray Waste to Pandaemonium. Or perhaps the river continues on, cleansed of its dark taint (no doubt with an all new dark taint to surprise bloods with. Maybe it's yet another branch of the Styx, leading somewhere else.)

One layer down, the titanic roots of Yggdrasil wind about Nilfheim. An lurking Helkyrie sees the vastness of the root hidden in the omnipresent mists and decides to follow them along. Everything looks the same for miles and miles until the temperature starts dropping and raising, both at once. A peculiar numbness fills the proxy of Hel as the mists clear, revealing the vastness of the Astal Plane in all directions. Ygdrasil's titanic trunk stretches beneath our intrepid explorer as far as the eyes see. After bribing a ratatosk Sensate with exotic wine brewed from something a hordling leaked, the Helkyrie follows a branch to the nearest plane. The silver expanse of the Astral slowly becomes the clear sky of Ysgard and the branch comes to a stop high above a pine forest. Looking behind, the branch disappears into the woodlands. Following it back, we're on the Astral again.

As all this is happening the famed travel guide Reneas, the Helkyrie's neighbor in Pluton, is eyeing the great mountain Olympus speculatively. It's gray, of course, and it's a slanty, rocky slope that goes disappears into the distance. As Ren climbs it (no easy task here) the colors of the shrubbery get slowly brighter, and the Astral Plane appears. Ren ignores it until the Githyanki attack. Fortunately, Ren's close to Olympus proper and a per helps him fend them off. The per checks Ren out, gives him the okay and leads him through a narrow path which begins in the Astral and ends in an Arborean road. Reneas thanks the per and runs off to meet his good friend Stimpeas in a local village 3-12 miles away.

  

How to the Pathsways Fit into the Rule of Threes?
(by Joshua Jarvis and Axyun Xunn)

Guvner theoreticians reckon that three major kinds of planes exist: Continuous Planes, Cluster planes, and Convergent planes.

Continuous planes are like the Astral or Ethereal. These are lone planes without association with other planes. Some scholars limp the Ordial in with these, but the existence of that plane's only a fact if you believe a certain medusa historian [see the Musée Arcane].

Cluster planes are the Inner and Outer planes where a single concept fills a group of planes. The strangest cluster plane is the Prime, here all the clusters (spheres) are within a single plane and are not planes unto themselves. One may almost say the prime is an intermediate plane with aspects of both the Ethereal and the Cluster planes. It's interesting to think that the Prime may one day evolve into a full fledged cluster plane.

Convergent planes are planes that travel through other infinite planes. An example of this is the River Oceanus. Winds its way through infinately long planes and somehow manages to travel from plane to plane even though each is infinite. As the theories go, these planes converge with other planes, and exist in the same space at the same time. Other convergents include the River Styx, Yggdrasil the World Ash, Mount Olympus and the Infinite Staircase.

Where are the Paths Physically Located?
(by Jon Winter, Alex Roberts, Wightboy, Truls Rostrup, Monte Cook)

Some bloods reckon these planes actually squeeze into the gaps between the other planes, and that's how they get their special properties. Locations like the burg of Crux on Yggdrasil aren't actually on any plane at all. The same goes for some Olympian burgs (especially those buried under the surface of the Mount) and the Infinite Staircase. Travellers on the Styx or Oceanus, however, never technically leave the plane surrounding the river in question...so it's not a general rule.

That's as maybe, but they can also wander in terms of where they connect. The roots and branches of Yggdrasil change with time (some say the World Ash is growing), slopes of Mount Olympus change with rockfalls and weathering, the meanders of the Styx and Oceanus mean charts (as such they are) need updating ever century or three. Lumped into this category are the realms of powers with no known plane, or those that wander.

Also, demi-planes might exist for powers whose alignment fits a plane's location, but who don't like the feel of the plane itself (How about an evil power who, for some reason, covets colours? Gray Waste for selfish, covetous evil, but it's all...well...grey.). Astral Conduits could pass through the space. Maybe the Hinterlands fold up to fill it entirely like a pathological curve.