This episode is likely to be centered on Daniel Faraday and is, in content and title, a companion to the brilliant season 4 episode “The Constant.”
Aside from Faraday, as you might expect, Desmond will also play a big role as there might even be a scene of him leaving the Army. This episode should explain what Faraday’s notebook meant by “Desmond is my Constant.”
Casting calls for this episode also include a possibly recurring character in her early 40s named Sophie, a British woman, and a 10-year-old child prodigy named George.