What Makes Smoke Render As Smoke?

Hi All,

I pulled down the Twister scene from Blendswap.

I have re-baked the simulation but when I render all I see are halo particles. What makes smoke render as smoke? Is there something else I have to turn on?

Using Blender 2.64 with Blender Internal.

Here is what I get.


Here is what I want


You using self illumination emissive particles, but you need absorption instead.