At the funeral of Michael Piper, the reading is announced simply as being by the Deceased's "favourite poet, Walt Whitman". Specifically, the text is the final 8 lines of "Song of Myself" Part 6, which starts, "What do you think has become of the young and old men?..."
In the scene with his niece and mother, Keith handles a plastic thermos featuring The Get Along Gang, American Greetings card characters who also had a short-lived cartoon series in 1984.
Alice Krige plays Alma in The Plan. In Ghost Story she plays Eva Galli / Alma Mobley.
As Nate brushes off his brother's pleas for treatment for his brain disorder, David says "You could die from this" and Nate replies "I could be in the wrong airplane at some point". This episode aired on March 17, 2002. In real life, just over 6 months before it aired, nearly 3,000 people died in the New York World Trade Centre terrorist attack on September 11, 2001. Several commercial planes were hijacked as part of the attack.
Claire is watching the film 'Badlands' (1973) on TV.