AMC’s “Rubicon” began so assiduously it was hard not to wonder if the show’s audience would die of old age — or boredom — before the major plot kicked into gear.

But now, with Sunday’s upcoming episode, the series has sprinkled enough bread crumbs where it’s become must-watch fare in my house, and the hours — dense and pensive as they are — actually seem to fly by.

Rubicon2 Much of that has to do with the casting, particularly Arliss Howard as a shadowy higher-up in the murky American Policy Institute, a government-backed research organization where nobody is to be trusted. Menacing, cool and casually gay, it’s hard to read whether Arliss’ character, Kale, is friend or foe, but he’s one of the most compulsively watchable figures on TV right now.

As for the plot, there was even an overt reference in the most recent episode to “Three Days of the Condor,” with someone asking whether the protagonist, played by James Badge Dale of “The Pacific” and “24,” was a “Robert Redford” kind of intelligence analyst. Given all the comparisons to paranoid thrillers of the 1970s, the question seemed particularly apt.

With the program building in interest, AMC can now point to a near-perfect development track record, the exception being a misbegotten reboot of “The Prisoner” that, at least, featured Sir Ian McKellen. “Rubicon,” too, is extremely well cast, from Miranda Richardson as the widow of a man who might have been involved in some vast conspiracy to Howard to stage actor Michael Cristofer as the API’s inordinately quirky, serpentine boss, who seems to slither around in his own cloud of brimstone. Plus, the show has what might be the best opening theme in TV right now — kudos to composer Peter Nashel — which is so good I refuse to zap through it.

OK, so it’s still no “Mad Men” (which is having an extraordinarily good year) or “Breaking Bad.” And to be fair, this is the kind of program that a broadcast network would probably be forced to cancel some time between the second and third act breaks in the premiere, underscoring the chasm that still exists between major networks and cable.Rubicon3

 “Rubicon” is nevertheless an unusually smart and demanding series, following somewhere between those aforementioned movies and “The X-Files” at its paranoid “Trust No One” best. Given that, AMC deserves credit for rolling the dice on it — and even saying yest to such a cryptic title — with another widely anticipated offering, “The Walking Dead,” due in October.

That last one’s about zombies, by the way, but right now, this little cable network — which didn’t get into the original drama game all that long ago — has a surprising amount of life in it.