When Shannon reveals her identity to Lex, she says "What's the matter, Lex? Don't you recognize me?" while undoing her hair and removing her glasses. This is a reference to Superman's disguise as Clark Kent, which famously consists of simply slicked-back hair and glasses.
Jane Seymour, who played Genevieve Teagu, also starred in Somewhere in Time (1980) along with Christopher Reeve who in turn played Superman in four movies and played Dr. Virgil Swann in two episodes of Smallville.
In Lana's dream, Isobel says "Je vais dormir seulement un peu" which translates to "I am going to sleep for just a little bit". Duchess Gertrude says, "Tu m'as trahie Isobel, maintenant tu vas mourir," which translates to, "You have betrayed me Isobel, so now you are going to die."
This is the first episode we see Duchess Gertrude, the ancestor of Jason and his mother, an important plotpoint that is the source of Thoreaux's revenge later in the season.
The opening of this episode is similar to the plot of the 1997 film Red Corner.