Opens with the quote, "Catch me when you can." This is from an 1888 letter claimed to be from Jack the Ripper that arrived with half a kidney.
Several of the names in the email contact list when Juliette is contacting Kelly are the names of various crew members, including this episode's writer.
Jack The Ripper was the nickname given to a unidentified serial killer who, in 1888, murdered Annie Chapman, Mary Ann Nichols, Elizabeth Stride, Catherine Eddowes, and Mary Jane Kelly in and around London's Whitechapel area.
The text of Kenneth's passport states his surname as "Bowes-Lyon" which is the British Queen Mother's maiden name linking him to royalty albeit not royalty from Vienna as in the series
The plot is centered on the legend of Jack the Ripper.