When the invaders destroyed the Fifth World, a few hundred priests, jaguar knights, coyote knights, pochteca, and royal by-blows entered the Temple of Tezcatlipoca in Tenochtitlan and never came out. Deep below the temple, the high priest of Tezcatlipoca spoke into the glass of a Smoking Mirror Engine, and opened the gate to a Sixth World. Once all had passed through the mirror, the gate closed, tipped forward and shattered into a thousand obsidian shards.
The refugees stepped forth into a Mirror Gallery deep beneath the Temple of the Netted Jaguar - a temple much like the one they knew in the dead city of Teotihuacan, birthplace of the gods. They cleared ancient rubble and ascended steep stairs onto the temple's platform. They saw the abandoned city, the birthplace of the gods, surrounded on all sides by a huge living megalopolis.
The living city reminded them of the Tenochtitlan they had fled. But unlike that island city, all the lands surrounding the lake had also been built out. And the entire lake was ringed with chinampas, with even more great causeways extending from all sides of the lake toward the Living City at its center.
The city itself was impossibly ancient and decadent. Their people spoke a tongue similar to the refugees, and their gods were similar as well. They wandered the Living City, listening to the people. They learned the name of the city was Xochiquetzatlan, the city that the goddess Xochiquetzal ruled with her male consort Xochipilli. A lush city, whose chinampas fed the lands to the south. A soft city, content to hand over a small portion of its surplus to the Olmeca as a tribute payment for peace.
The new arrivals retreated to the abandoned city of Teotihuacan. The priests and jaguar knights conferred with the royal by-blows. This Sixth World looked ripe for conquest. They began with a plan to take this city of Xochiquetzatlan. Then they would deal with the Olmeca.
But their first step was to build a camp, and soon enough a stronghold in the dead city of Teotihuican. From there, they could begin to exert their power in the Living City, and explore this Sixth World.