For the first time I started screaming, "Oh my god! Oh my god!" while listening to W.A. Cool feeling.
The reason was because of the gas in the mortuary. It sounds like the gas is escaping from the decomposing bodies. (Not the other way around, where the gas decomposes the bodies.) The pressure of the gas building up within the bodies causes it to escape as a haze. I wondered if this could be a very ancient agent that seeped underground, escaping through volcanic and tectonic faults, after enough pressure had built up around the globe.

Or, imagine a new ground zero brewing from the 6 million missing decomposing bodies buried under L.A.

Tardust did seem to have an answer that he was holding out from Riley and Burt. He gave the same type of answer as Skittles when Micheal and C.J. asked for his help. Skittles is worried that Ink will know that he help them and Tardust says that Scratch will know that he helped Burt and Riley. So, he's been telling them of places that she could be... Riley:"Where is she?" Tardust: "Dantooine. She's on Dantooine." But he left out a particular one.