 In "Patriot Down" (S07E23) Following the murder of SSA Lara Macy, Tony inquires as to who killed "another female NCIS agent", referencing Kate's passing.Kate's sister, Dr Rachel Cranston, was introduced during "A Man Walks Into a Bar..." (S08E14), in which she was conducting mandatory psychological evaluation of the MCRT.Flashbacks of archive footage, alternate takes and deleted scenes including one from the Season 2 episode, "An Eye for an Eye", are used for illustrating the memories of Gibbs, DiNozzo, Sciuto, Dr. Mallard, McGee and Rachel as they remember their deceased friend and sister.