16 seasons is an awful lot of tv show. It's been the most popular show in the world for much of that time due to a simple formula. It's always been fairly light viewing, but with solid writing, direction, acting and production. A few lousy holiday specials aside, it's never been guilty of jumping the shark. It's inevitable, however, that a show of this longevity will, from time to time, start to feel stale.
This is not one of those episodes. I'm not talking about the twist in the end. That's magnificent, and it's going to be a brilliant story arc for the rest of this season, but it's not what makes this the finest hour of NCIS in many years.
They did so much more with the cast than they usually muster. The rare depth they give to Gibbs, Ellie's and even Ziva's characters is wonderful. Except for the jar of water thing. That was useless. But the character development isn't it either.
It's the story.
This isn't your standard "dead petty officer" procedural. The story is absolutely riveting. It's been reflected in the news a few times recently, and it's horrifying subject matter. It's handled lightly - this is still NCIS - but believably, and with dignity. A couple of scenes had me in tears, and this show has never had that capacity before.