How NCIS pulled off its Season 16 finale surprise

TV Guide

In order to keep Tuesday's surprise cameo a secret, the scene was never included in any script and a skeleton crew was used to film the special guest, who arrived via a back gate entrance after the rest of the crew had wrapped. "This surprise moment is just the beginning," said NCIS showrunners Frank Cardea and Steven D. Binder in a statement, announcing that the surprise will continue next season.