[s4e8] Requiem -

: 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.

: 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.

(Season 7, Episode 22 / Sometimes confused with S4)