One of the branching timelines that resulted, where mankind ended up killing itself off against the Foe. Survival and the inevitable repair of the dying world is left to the few dolphins that remain, though that number steadily decreases over time.
The third branching reality where dolphins have come to mirror mankind if traits and flaws. History repeats itself in a new species; The oppressive Clan and frightful Outcasts carefully swim a fine line, technology is created and both sides are cruel without question, pursuing only their own ambitions.
The extinction of both sides leaves the Foe to feed off the remaining life on Earth. The Guardian chimes as it send ripples through time and space, calling those who are aware of the inevitable end to a final, bloody cause.