The physical plane is the part of the cosmos where all of the elements intermingle. It is by nature multifaceted and complex in ways that the element planes are not, since they are made of and populated by a single element. All matter consisting of more than one element initially manifests in the physical plane. The plane is split into two worlds: the material and spirit.
The Element Guardians exist in both the material and spirit worlds simultaneously. In the material world, they regulate the flow of elements between the physical and element planes. In the spirit world, they watch over the Lighted Path which souls walk before birth and after death.
A major feature of the physical plane are the stars, known as suns to many of their local planets. They are the repository of nearly all Fire in the cosmos and serve a dual role on the physical plane. In the material world, the stars are the source of life via the heat they project out from themselves. In the spirit world, they are the center of human consciousness and store the souls of those waiting to be born again and live a life in the material world. The thoughts of the souls within, if any, as well as their reasons for leaving to walk the Lighted Path and live a life in the material world, are unknown, possibly even to the Pilgrims.
The material world is one with fixed natural laws and is considered by many to be "the world," as it were, because it is the land of the living. Souls must pass through the spirit world at birth and death in order to reach this place and live their lives. Nearly all humans, once born, stay in the material world until they die. Much is said elsewhere of the material world and its inhabitants, so the description here is brief.
The Lighted Path is the protected conduit between birth and death and is watched over by the Element Guardians. When a soul wishes to be born in the material world, it leaves the source of life and shared human consciousness, the sun, and walks the Lighted Path. The thoughts of those in the state before birth are unknown, as are their reasons for leaving to live a life in the material world. Death is the return to this state.
Some souls eschew the Lighted Path and remain in the spirit world in order to guide and teach, others to prey on unwary souls, and some by accident. Powerful shamans may choose to stay, as they become aware of the Lighted Path during their initiations. Special rituals and aid from spirit guides facilitate this transition. However, one cannot simply walk off the Lighted Path by chance. The vast majority of souls must take this road, under the eyes of the Element Guardians.
Souls who die imbalanced due to infusion or some other accident involving element energy are unable to find the path. Their eyes are dimmed and they cannot see the Lighted Path. As a result, they "haunt" the material world and flit between the two at random, unable to tell the difference. They sit between life and death, unable to enter either. Shamans can find them and help them, but it is dangerous. Depending on where the soul has wandered, they must travel to wild areas and expose themselves to predators. The lost souls themselves are dangerous and unpredictable too, and few shamans choose to make this their profession.