Warning: SPOILERS for the NCIS: Origins two-part premiere “Enter Sandman” are ahead!

NCIS: Origins has premiered on CBS, and Mark Harmon’s role in the first episode has been revealed. It was previously reported that Harmon, who serves as executive producer and narrator on the NCIS prequel,

Long running series 'NCIS' spawns another spin-off with 'NCIS: Origins,' which delves into Gibbs' early years.

Origins is great news for the franchise after his NCIS exit, but it also sets up a big problem for the prequel.

Mark Harmon remains an important component of the NCIS Universe, even though he is no longer starring on the flagship show. NCIS fans already knew Mark was part of the new prequel show, but nearly everyone thought it would only be behind the scenes.