Last night's NCIS investigation had the agents barking up the wrong tree almost the whole time. A dirty bomb was indeed in play, as advertised, but not for the reasons we expected.

The episode title hinted at a multi-layered plot, something NCIS pulls off so well. Check out our episode recap for the basic plot details. Now, here's our review of "Masquerade" ...

There's so much going on in each episode that it's hard to believe it hardly ever feels forced, cliched or tied together too quickly. This show is extremely well-written. Period.

As the team investigates the death of Lance Corporal Ramon Vega after his car explodes in a police chase, they uncover traces of cobalt-60, a radioactive, dirty bomb component.

The backdrop, which involves Director Vance, is that the U.S. Senate is about to vote on a defense bill authorizing billions in contracts. Vance complains about the outsourcing.

Gibbs and McGee work to dismantle the bomb at the bus station.

With the bill up for a vote, Vance can't believe the timing of the dirty bomb fiasco, which has now been leaked to the press, until he and Gibbs realize the connection between the two.

There was a bomb out there, but it was amateur night. Gibbs and McGee were able to disable it, and figure out that the true goal of whomever orchestrated this is fear, not casualties.

A private intelligence firm hired by the government made up the existence of a Peruvian terrorist group, Libertad Nuevo, and used Roman as its pawn to send D.C. into mass hysteria.

It worked, until Gibbs and Vance bluffed their way to a confession from the intelligence firm's owner. Those two are fun to watch working in tandem ... we're scared sitting on the sofa.

There were plenty of intriguing character interactions last night as well.

None other than M. Allison Hart is back defending Roman Vega and his brother, to whom he placed a frantic call before the car crash, and who was the investigations original focus.

We saw Rena Sofer's attorney character a few weeks back and know she also represents Col. Milton Bell, who Gibbs sent away to Mexico to face bounty hunting charges late last year.

NCIS clashed with her throughout, and even though her clients turned out to be innocent pawns in the case, she left quite an impression on Mr. Gibbs. Sorry, Special Agent Gibbs.

We still don't know the agenda of M. Allison Hart (Rena Sofer).

After he cracked the case, she showed up inside his house, lurking in the dark. Gibbs notes again, correctly, that she keeps taking on seemingly random cases that connect to him.

The burning question is why. What is Hart's deal? Can she be trusted? Gibbs doesn't think so, but he's attracted to her just the same. They move in for a kiss as the credits roll.

We're hooked. Sparks are flying between Sofer and Mark Harmon, and we're as confused / intrigued as Gibbs by Hart and why she inserts her no-nonses legal self in his business.

Another great sequence involved Tony and Ziva investigating the warehouse thought to be where the terrorists were building the bomb. No mention of Paris. Just Somalia.

As Ziva posited that terrorists may see themselves only as defenders of their way of life, Tony broached the topic of Ziva's time as a captive in Somalia (see Season 7 premiere).

This is another thing NCIS pleasantly surprises us with often. Broaching a loaded topic like that without pushing a particular political angle is refreshing and thought-provoking.

RANDOM THOUGHTS:

• Classic Abby moments: Staying in the HAZMAT suit because it sounds cool when she walks, and getting upset when her "presentation" to McGee didn't sync just right.
• Who's the bigger McGeek: McGee himself for attending an online wedding, or Tony for taking tap-dancing lessons (revealing he sees a therapist was also a nice touch)?
• Great integration of the political wrangling that goes into defense funding with an actual case. The two are obviously closely tied, but this is rarely explored by media.
• Speaking of media, what would ZNN even stand for?

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