Here's the artist's explanation from the derby thread.
I got curious and read the rest of the story in the link he provides. On page 2, the two-reed glyph is translated as "meal". So here's my interpretation:
"A strange chariot arrived on tracks of fire, bearing a bushy-headed man and a boy who traveled on a board. They could not find any of their device's food to make it go 88 miles per hour, so they decided that it needed to eat lightning, which was coming. They brought their chariot to the top of a tomb and let it fall at just the right time for it to be struck by lightning at the base of the tomb; and then the chariot and its riders were gone, leaving only tracks of fire."
I'm waffling on this. I love the idea, but damn it's going to take a long time to read, and I'm not used to being gawked at for quite that long.