Sativa's people have formed the belief that you are reunited with the spirits of your ancestors on another plane which apparently takes the shape of a great Vault in the sky.

She's not to clear on whether that includes just the people n her tribe, or everyone who dies or if it's going to get crowded with the accumulation ancestors, but either way she's in no hurry to find out first hand. It does sound nicer than just nothingness while your bones dry out in the desert sun, though.