Even run-of-the-mill NCIS installments rarely disappoint, but how good are these end-of-season multi-episode arcs? It seems like every year around late April or early May, the intensity is kicked up several notches.

Tonight was no exception. With two more episodes remaining in season nine, "Playing With Fire" was essentially the second chapter of a four-part NCIS mini-series ... possibly even longer than that.

Knowing Gary Glasberg, Shane Brennan & Co., this will no doubt stretch into the fall in some form. The way it's going after last week's "Rekindled" and now this evening, I doubt there will be many complaints.

It's been a team effort from the start in a case that brings the agency's military roots to the forefront. We all enjoy NCIS for the characters, but remains a Navy show, and it raises the stakes when this is highlighted.

Because of the nature of the deepening mystery, the episode was light on action for most of the hour, but the compelling, perfectly-paced story more than made up for it. When the show commits itself to continuity over multiple weeks like this, the stories are less rushed and often feel more organic.

It was, pardon the expression, another slow burner, and a good one at that.

Much of the episode was spent on the obvious - connecting the Baltimore arson with the fire marshal's demise and the explosion on the U.S.S. Brewer. Once that link was established, it was on to the next target.

Tony and Ziva, at their bantering best, were dispatched to Naples with Stan Burley and tasked with catching the perpetrator in the act of trying to blow up a nuclear-armed aircraft carrier. No pressure.

Their European mission led to some fun exchanges, as did Ziva's ill-fated pilates weekend and Tony's rabid curiosity in general. Obviously, Tony's a little obsessed with her, but he's more obsessed with gossip.

The two of them, along with McGee, offered consistent comic relief and character insight, but never - and this can be a difficult line to walk - to the point where it overshadowed any of the crime solving.

The night's second most intense moment had to be aboard the Benjamin Franklin, when Burley took a flying knife to the shoulder. Fortunately, he'll come out of this fine, thanks to the aircraft carrier's two new "enlistees."

DiNozzo's jealous, overgrown frat boy ways and sarcasm serve as his calling card, but he always comes through. He and Ziva make a great team, even if it irked him that she "outranked" him as a faux Naval officer.

The most intense scene came when Gibbs had the would-be arsonist thinking he was en route to Guantanamo Bay thanks to the Patriot Act. Not a bluff you want to call. Amid Gibbs' threat, he gave up his boss.

Or gave up what little he - or anyone - knows of the reclusive investor anyway.

We now have a name and a face behind these acts of terrorism, but it was not a North Korean despot or a man anyone has seen in person in the past year. It's Harper Deering (The West Wing's Richard Schiff).

Beyond apparently bankrolling the attacks, Deering's role remains unclear. Schiff is set to appear next week, so we'll likely get a greater idea then of whether he's the mastermind, or just the international go-between.

The Korean code was (relatively) easily deciphered, but his motive is another story. This is a new kind of villain, one with all the right connections, potentially dangerous information and considerable financial wherewithal.

Did anyone not feel their pulse quicken when the entire room stood ramrod straight as Gibbs posted Deering's picture over that of Osama bin Laden - killed one year ago tomorrow (May 2, 2011) - on the Most Wanted List?

That moment left no doubts as to the agency's solidarity, or the seriousness of the task at hand. Great to see Gibbs rally the troops, so to speak, for the battle ahead. Next week can't come fast enough.

Somewhat removed from the terrorist plot, but still connected indirectly, especially near the end, was Ducky. Naming Jethro executor of his estate was a touching gesture, as was his charitable bequest.

Seeing the slain officer Ramsey's children made the doctor's decision easy regarding where to leave the bulk of the money he'll never live long enough to spend - the Marine Corps Scholarship Fund.

Classy move to plug that organization via a beloved character like Ducky, who first revealed his surprising wealth at Gibbs' house. You know anytime there's a scene there, some secret's going to come out.

As for the time when Dr. Mallard passes away, don't look for that to be a given that future plot line, thankfully, as David McCallum signed a two-year contract extension with CBS this week. He's going strong at 78!

A few random thoughts and stray observations before turning it over to you:

• You have to love the resurfacing of Stan (and Ziva's bikini photos), YEARS later.
• Next week is Palmer's bachelor party. Thoughts on what Abby will (or should) plan?
• His absence was explained, but it feels like Vance should be involved, doesn't it?
• Also absent, but getting a brief mention, was Jason King (Gaius Charles).
• Crackers and apples, people. Remember that.

What did you think of tonight's NCIS? Discuss in the comments below!

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.