 Sasha Alexander recorded voice clips for this episode.Later, in "Nature of the Beast" (S09E01) several references to Kate are made, whilst Rachel Cranston is referred to as "Doctor Kate's sister".During "Life Before His Eyes" (S09E14), an alternate-universe version of Kate is shown in which she was never killed by Ari, is still an NCIS agent, and is married to DiNozzo with a baby girl named Kelly.