Premise: "Dark Knight Court" is the sixteenth episode of the 24th season of "The Simpsons" and the 524th episode overall. It originally aired on the Fox network in the United States on March 17, 2013. The episode is dedicated to Janet and Maggy Reno's brother, Robert Reno, who died of Alzheimer's disease.
Hypothesis: Robert Reno had Alzheimer's for 3 years.