Until recently, I was ambivalent about AMC's 'Rubicon,' but the last couple of episodes have turned me into a solid fan. Sunday's episode and the Sept. 5 outing didn't just have the effective atmosphere, excellent acting and memorable characterizations I'd come to expect.

In the last couple of weeks, the pace notably quickened as well, and the show featured the kind of multi-layered, ambiguous yet compelling storytelling that is that hallmark of AMC's flagship dramas, 'Mad Men' and 'Breaking Bad.' Star James Badge Dale had a featured arc in the third season of '24,' another intelligence-oriented drama, but 'Rubicon' is the show that has really allowed the actor to shine.

Normally I'm all about the mythology, and it's good that 'Rubicon' finally seems to have gotten a handle on the show's overarching conspiracy, which seems a lot less opaque now.

And while it does need some kind of story engine to keep it perking along, lest it become the Show About People Who Stare Out Windows, 'Rubicon' actually works best as a nuanced, subtly observed and wonderfully acted character drama.

So many dramas have trouble creating characters that feel specific and real, but 'Rubicon's' done a stellar job in that department. Sure, there's a hydra-headed conspiracy afoot and a cabal of wealthy men probably doing terrible things, but I really care about whether the brilliant but broken retired analyst Ed will go completely off the rails. I want to see what weirdly ominous pronouncement Truxton Spangler will make next. I'm wondering about Kale Ingram and what he's really after and why he thinks Will can get it for him.

There are so many questions of trust that reverberate through every episode. Can the analysts trust the data in front of them? Can the API employees trust each other? Themselves?

In the past few years, shows about people who work in intelligence have proliferated like crazy and there are more coming down the pike this fall. But very few of them show the personal and emotional cost of having this kind of information inside one's head.

For people who are at all sensitive or thoughtful -- as API employees Will (James Badge Dale), Tanya (Lauren Hodges), Miles (Dallas Roberts) and even Grant (Christopher Evan Welch) are -- the sheer weight of the information they process, as well the consequences of the decisions they make, eventually burns a hole in their soul.

The evidence isn't hard to see -- Tanya drinks and takes drugs to forget the things she reads and thinks about, and I'd bet more substance abuse is ahead after what she saw in Sunday's episode. The look on her face says she will never forget the image of the terrorist being tortured by Jordanian operatives. She stays and she does her job, but it costs her part of her soul.

Miles is extraordinarily good at his job and more able to keep himself steady in difficult situations like that, but he can barely admit that he's lost his family, and it's not hard to surmise that his job had something to do with the split. It's not like you can leave the job at work (though he learned the hard way that you really shouldn't take files home). The one thing that Miles is really good at has put a wedge between him and the people he cares about most.

Will also throws himself into the job rather than face his empty personal life. And while Grant still has an intact family unit, his polygraph results deeply unsettled him. Apparently he's already mentally committed infidelity, all that remains is for him to get around to the actual deed. If the staff is searching for role models, Kale (the terrific Arliss Howard) isn't exactly someone to look up to. He's efficient, but scary-efficient. He doesn't seem quite human on some level, and is that any way to live?

All these people have given up part of themselves to do something really difficult -- to find patterns and clues about the threats to America. What 'Rubicon' makes clear is their analysis comes at a price. This isn't Jack Bauer kicking down doors, but it's every bit as gripping as that, if not moreso, given the ambiguous yet urgent nature of their jobs and the layers of fluctuating trust among the characters.

The Sept. 5 episode, which had the FBI investigating a leak, recalled the Aug. 15 episode, 'The Outsider,' in which the group had to decide whether a certain terrorist target should be bombed (collateral damage among innocent civilians would be unavoidable). Both episodes had self-contained elements that wrapped up by the end of the hour, and both focused intently the effect of those situations on the characters. In the case of the Sept. 5 episode, the leak was a MacGuffin that allowed us to see Miles' nerves over the lost file, Tanya's jitters over her drug test, and the group's profound relief at being able to focus on their most recent case in order to get their minds off everything else.

In Sunday's episode, when Miles and Tanya debated the implications of what they were doing at that rendition site, their conversation had a moral urgency that is often missing from shows about intelligence work. It wasn't always the case, but '24' eventually fell into a pattern of showing Jack's "whatever it takes" methods to be the right ones.

Knowing as much as they do, Miles and Tanya can't see everything as black and white. They certainly know more than most of us do about the evil that people are capable of, and they are willing to live with the decisions they make about the responses to those threats. But they also know that they themselves and the people being investigated are usually pawns in much bigger games. Smiling Bob from the CIA wasn't exactly telling them the whole truth about anything.

I don't mean to beat up on '24' too much; it certainly worked as both a character drama and an adventure serial for a surprising number of years. Yet the Fox show's increasingly simplistic answers to complex questions was problematic (though its biggest problem was that it simply repeated the same kinds of situations and threats too many times). And it showed what his job cost Jack, though in later seasons, that aspect of the show got melodramatic to the point of tediousness.

Another issue was that over time, '24' killed off a lot of good characters and left its lead character increasingly isolated and alone, whereas in 'Rubicon,' you sense that Will would very much like to make a real connection with another person, not just connect the dots of fiendishly difficult intelligence puzzles. Like 'Burn Notice,' 'Rubicon' wisely realizes that the stakes only matter when the hero's family (biological or otherwise) is under threat.

If I have one concern about 'Rubicon,' it's that I'm not sure where it would go if it gets another season. The conspiracy that Will is investigating appears to be very insidious indeed. Would they continue to tolerate a Mulder in their midst? It seems doubtful, as doubtful as the idea that Will and Kale could bring down such a powerful and connected cabal.

Having said that, 'Rubicon' has developed to an addictive character drama, and if the writing keeps up with the abilities of the stellar cast as the rest of season 1 unfolds, it'll be well worth our while. If the show continues to focus on fussy Grant, lost Tanya, twitchy but lovable Miles, chilly Kale, scary/weird Truxton and brooding, evasive Will, I'll keep watching.

The secrets they choose to keep and reveal are getting more interesting by the week.