The Froth - the mortal realms - is the collection of all that we think of as the multiverse, home to uncounted worlds and unimaginably vast spaces. But those who think of the Froth at all think of it as its own entity, rather than what it really is - the meeting and mingling of greater and immeasurably older forces, like the foam on the crests of waves, which is a mixture of the air above and the sea below.

The Realm of Chaos, the domain of its titular Extrinsic, is where a large part of the great mixture comes from. It is unnavigated and unnavigable; there is no map, and no compass. It is as hard to cross as an uncharted continent, yet every destination is merely a footstep away.

All that is born from the Froth is composed of both Order and Chaos. For a mortal to physically manifest in the Realm of Chaos unprotected is to leave behind all in them that is Orderly, and it is safe to say that no one subject to this fate returns alive; they, and every atom of their being, are pulled apart, all that they are fading away into all that everything else is.

There remain only two ways to survive the Realm of Chaos unscathed. The first involves rare and powerful magic, exercised by a third party, which places the visitor in a protective cocoon; but in such a situation the visitor becomes confused as different spaces and times run together, and runs an increasing risk of going mad until returned (again by a third party) to the Froth. The second involves the goodwill of Chaos, who can act to keep a mortal intact if it so chooses - and, indeed, if it notices in time - but will typically only do so if it finds them interesting enough to hang onto for a while.

Those very few of the second sort who have been and returned have difficulty describing what they see, if they retain enough sanity to understand and answer the question. There is talk of being suspended among roiling clouds of endless colors, of light flickering like fire or lightning writ large, of sights half-seen and noises half-heard.

While there can be said to be life in the Realm of Chaos, it is of a very different kind than that in the mortal realms. It is strange and mutable, to the point that even its reality is tenuous; a Chaotic life-form is as much an idea, a dream, or a ghost as an actual thing, and which it is at any given time - or even whether it is an imagining of the observer or of Chaos itself - may be indeterminate.

Each behaves as it likes, without supervision. Some are as immortal as they want to be, others last a microsecond; some eat each other, others drink yellow or devour poignancy, and yet others consume nothing at all.