The soundtrack features several Beatles songs, including "Yesterday", "Lucy in the Sky with Diamonds" and "Here Comes the Sun". Coincidentally, this episode was originally broadcast on December 9, 1980, one day after John Lennon was murdered by Mark David Chapman.
Mavis was born in 2015.
This episode takes place in 1980, 2130 and 1988.
Earth was devastated by the Holocaust of 1999.