: For a broader look at the secrets revealed during this era of the show, the Raymond Reddington Wikipedia page summarizes the "imposter" theory and the role Kathryn played in hiding the truth.
: Titled "Gold, Glory & Custer: Requiem Part II," this episode is praised by history buffs for its authentic use of Lakota dialogue and historical figures like Chief Touch the Clouds. [S4E8] Requiem
Though it is the Season 7 finale, "Requiem" is one of the most famous episodes in the series, featuring the abduction of Fox Mulder. : For a broader look at the secrets
: This detailed article from Pop Culture References explores how the episode serves as a major clue to Reddington's true identity, showing Kathryn's life as Liz's nanny and her initial bond with Katarina. : This detailed article from Pop Culture References