The was the last television show or movie to be directed by Felix Feist who died of cancer at the age of 55, 6 months after The Enemies aired.
The strange room wheee Gen Tau appeared to be much larger the Crane a Nelson is known as an Ames Room. It was first built by Aldbert Ames, Jr., an ophthalmologist, in 1946 which based on a concept by Hermann Helmholtz.
This episode takes place in the 1970s.