From the introduction:
A snake so big that it defies measure forever devours its own tail. Each of its vast scales is a strange and unique realm called a Plate.
Each Plate is governed by unique environments and strange juxtapositions of mundane and impossible things. Yet, they all share the same peculiar relationship to the cycle of life and death.
Players take control of Souls, assuming control of their current bodies and when those bodies die they assume control of the next incarnations in line (which usually happen to be very nearby at the time of death by pure game-immersion-maintaining coincidence. Perhaps your soul is drawn by some invisible string of destiny?).
Souls live longer than bodies, bouncing between corporeal forms. Unbound by the limits of time experienced by mortal bodies, the same soul might inhabit multiple people alive at the same time and can even jump between Plates. In rare cases, a soul can even jump way back or forward through time upon death.