In the episode, the senior citizens of South Park are killing people with their dangerous driving, and the residents feel that they are no longer safe on the streets.
[1] At the South Park Farmers' Market, Father Maxi holds a memorial service for nine people who died the previous day when they were run over by an elderly driver.
The news covers the recent rash of senior-related driving tragedies, mentioning that the DMV was planning to suspend driver's licenses from senior citizens over 70 years of age.
The military arrives and the seniors list their demands: their driver's licenses, more money for Medicare and keeping kids from skateboarding on the sidewalk.
Randy tells the boys that the seniors were able to organize so effectively because they get up earlier than everyone else, representing an advantage over their offspring, who prefer to sleep late.
After fleeing, the boys resolve to board up the town's Country Kitchen Buffet restaurant in order to cut the seniors off from their collective food supply.
Stan also tells his grandfather that he should be proud to be a senior, but he should realize that he is a killing machine when he is driving, an assessment that Grandpa accepts.
The episode, according to the creators Matt Stone and Trey Parker, was partially inspired by the case of George Russell Weller, an elderly man who, in 2003, accidentally killed 10 people at a Santa Monica farmers market by driving through the crowd.
[1] When Randy and the kids are running up the stairs whilst trying to hide from the elderly drivers, a man's corpse swings from a doorway, a reference to the slasher flick Halloween.
"Grey Dawn", along with the fourteen other episodes from The Complete Seventh Season, were released on a three-disc DVD set in the United States on March 21, 2006.