Even at the height of “Homeland’s” best era — and it was a considerable height — it was hard not to think about what would happen if the show fell off the tightrope.

And let’s face it, many of us were afraid the “if” in the preceding sentence was actually a “when.”

“When” came to pass; “Homeland” went off the rails in Season 3 in ways that did a great deal of damage the show’s credibility in any number of areas. The forays into Dana-land were pointless, the overwrought approach to the central romance was unfortunate, and people who were supposed to be good at their intelligence jobs were demonstrably bad at them (and got promoted!).

And yet, believe it or not, I approached this season with an open mind, or a mind as open as it possibly could be. It helps that there’s just so much TV around these days: I can barely recall shows that premiered last month, let alone revive TV beefs I had last year.

If time doesn’t heal all wounds, its passage makes it harder to get exercised about most of them, and I was willing to follow my semi-forgetfulness about the show’s missteps with forgiveness. Like many fans who thought “Homeland” lost its way in Season 2 — around the time Carrie stumbled through an abandoned factory waiting for Abu Nazir to pop up like a jack-in-the-box — and like a lot of loyal viewers who thought things only got more frustrating in Season 3, I wanted to care again. I wanted to enjoy the show’s unique mixture of suspense and character studies. I wanted to contemplate the surveillance state through the eyes of deeply damaged characters. I wanted to ride shotgun on nail-biting ops while Saul looked sad about things. Call me a corkboard-embellishing crackpot, but I wanted to believe.

Like Benjamin Button, though, “Homeland” appears to be aging backward; it started out as a mature tale employing a sophisticated arsenal of dramatic strategies, but it has gotten more adolescent over time. Another way to sum up the evolution of “Homeland” from Season 1 to Season 4 is to say that it used to approach characterization with a scalpel, but over time, it began using a hammer instead.

I don’t want to give anything away about the various plot threads of Season 4, but there’s a scene mid-way through the second episode that typifies the blunt-force characterization “Homeland” now resorts to on a regular basis. We all know that Carrie is a person who fights dangerous impulses, and Claire Danes is such a good actress that it’s very easy to read those impulse on her face. In a key scene, you can see a very dark thought flit across Carrie’s face; it’s extremely obvious what she’s thinking about. And I don’t think it’s wrong for “Homeland” to show Carrie wrestling with that thought.

But to make her begin to carry out the action suggested by the bad impulse fails to add anything useful to the story and to the characterization of the CIA operative. More importantly, to show her do this thing makes it crystal clear that “Homeland” is now simply afraid of ambiguity. Most viewers would have understood what she was thinking about and why. Nobody needed to see her actually take that action for as long as she did before restraining herself, but “Homeland” 2.0 keeps on spelling things out and hammering them home with that big mallet it carries around.

That flight from subtlety is truly odd, given that many of the show’s best moments had been all about ambiguity. When “Homeland” worked, it often worked because not everything was spelled out for the audience. Sometimes we were groping in the dark — for meaning, for information, for connections — right along with the people on the screen. There used to be mysteries to savor as “Homeland” explored the ways that professional liars exposed their deepest truths, but now too many moves and too many dilemmas are spelled out in blinking neon letters.

There is a flatness to the supporting characters — Saul’s wife and Carrie’s sister are now garden-variety Prestige Cable nags — and a measured predictability to the overall story that drains too much tension from even the sight of a wig-free Corey Stoll. Yet Mandy Patinkin and F. Murray Abraham are still fantastic, the show still employs top-notch directors and “Homeland” can still rustle up an atmosphere of tense isolation when it needs to. All in all, many of the tin-eared elements would more or less tolerable if I were still intrigued by Carrie Mathison, whose stubborn doggedness was balanced, in the early days, by her tendency to be right about things and good at her job. This season, right or wrong, she is simply rude in ways that drained me of interest in her personal and professional concerns.

To be clear, I don’t need to like Carrie, and I have no problem with her take-charge tendencies. However a show that’s now mainly about her should make me invest in her goals, but “Homeland” keeps on doing the storytelling equivalent of shooting itself in the foot. On this show, grown people do very dumb things and yet we’re expected to buy that they are big shots with important jobs.

Case in point: Apparently Carrie — who starts the season with the most important CIA posting in Afghanistan — does not know that infants are never, ever supposed to ride in the front seat of a car. I’d bet money that a random polling of 5-year-olds would reveal that most of them know this. It may be a small thing in the big picture, but seeing Carrie do something so boneheaded took me out of the story completely (she has two nieces; how does she not know this?). It made me wonder how in the world anyone would trust her with, say, a middle-school field trip, let alone a geopolitical hotspot.

The problems with this season of “Homeland” point to deeper issues and a seeming unwillingness to venture on to the road less traveled. Without Brody in the picture, the show had a chance to reinvent itself, and I was ready and willing to embrace “Homeland” 2.0, even if it was going to broadcast on a different frequency, so to speak. A tortured, impassioned folie à deux drove the best eras of the show, but I was willing to see what “Homeland” would do as it attempted to evolve past that distinctive early dynamic.

Apologies for the vagueness, but like a CIA operative, I don’t want to say too much. Suffice to say that when it comes to the personal lives of two major characters, what Season 4 intimates about their bond and their future comes off as a contrivance, at the very least. I understand the urge to put the band back together, but not if they’re going to be playing the same old song.

I loved many seasons of “House” and “The Office,” but I had to give up both shows when they went in directions that didn’t just tarnish my affection for them but actively began to destroy it. I think I’m at that point with “Homeland,” but like a well-trained espionage agent, I just don’t want to admit the truth.

The two-hour season premiere of “Homeland” airs Sunday at 9:00 p.m. ET on Showtime.