Robert Johnson was a young, and by all accounts untalented, boy who, in the early 1920s when he was in his late teens, would hang around bars listening to the Blues musicians of the day. He dreamed of being able to play like them. From accounts of his contemporaries, he disappeared for a few months and when he resurfaced he could play Blues better than everyone. He shot to fame almost over night. His music does feature many occult references, and the legend grew that he had sold his soul to the devil in return for talent and fame. He died at 27, under mysterious circumstances. There are several different accounts of his death, and he left behind at least three women claiming to be his widow. It is unknown if or where he was buried. To this day he remains an artistic legend, and those who remembered him maintained till they died that they had never seen anything like him before or since.
The song "Crossroad Blues", from which this episode takes its title, is playing when Robert Johnson makes his deal with the demon at the crossroads. The version used is actually sung by the real Robert Johnson. It is the only recording ever made of him singing that song.
The doctor is hiding out in Baskervilles Motel - a reference to Arthur Conan Doyle's "The Hound of the Baskervilles", a Sherlock Holmes mystery centering around mysterious gigantic black dog.
The actress playing the demon who visits Robert Johnson (Christie Laing) is the same actress who played Lori's roommate in Hook Man (2005) from the first season.
Ironically, there is a "Beware of dog" sign on Evan Hudsons gate.