Big Love — HBO's beguilingly wonderful melodrama about a family living on the fringe — returns for its fourth season on Sunday night. You really should watch it. If you initially wrote it off as unsympathetic, give it another chance.

We'd been excited for the show's premiere back in 2006, it just sounded so intriguing and Under the Banner of Heaveny. Mormons and polygamists and evil sect cults! But then it aired and it was just so... angular and strange. None of the characters were likable, not abhorrently misogynistic patriarch Bill (played by Bill Paxton with his usual dead-eyed drawl), and not his wives — long-suffering first wife Barb (marvelous Jeanne Tripplehorn), second fundie wife Nikki (the sneaks-up-on-you Chloe Sevigny), and third chipper child bride Margene (delightfully annoying Ginnifer Goodwin). There was just nothing to grab onto, nothing to relate to in any tangible way. These were antiquated people living in an understandably condemning modern world. Why would we want to root for this family when the very structure of the clan was so inherently fucked up?

The show just didn't have any of the sly universality of a masterwork like The Sopranos, a series about even worse monsters that still managed to seem simpatico with us regular Americans. Big Love was as weird and alien and quietly menacing as the rocky state in which it's set. We know lots of people who, after a few episodes, said "Nunh uh" and turned the channel to something less opaque and less ugly. And we didn't blame them for it! But for some reason we stuck with the show, hoping for two seasons that it would evolve from solidly-made moral thriller into something as grand and sweeping as HBO at its best.

And that then happened! Something started firing with the writers and actors and directors and cinematographers during last year's third season, and Big Love actually became *big.* Stones we'd long been eying were finally unturned, and the true sad theme of this show — that this is a cruel kind of faith, one that devalues individuals while pretending to uplift them — was cast into light. And it was also just exciting as hell, with politics and zealots and death and sex and pervy maybe-incest and secret pregnancies. Big Love isn't as nuanced a show as the tremendously good Mad Men, but it's blessedly not weighed down by all the real and imaginary symbolism that that series has been freighted with. Big Love is freed by its outre weirdness, it can do almost anything because we've been taught and inured to expect almost anything.

Not that the show goes hog wild just for the hell of it. The other wonderful thing about the third season was how deeply humane it was. These archetypes — the sad wife, the crazy wife, the naive wife, the evil prophet, the horny son — were given the rounding and shape they'd been lacking in previous seasons. Essentially, we really got them as people, not just as oh-weeeeird-look-at-that crazy Mormon folks. The show's major Achilles heel, its biggest dealbreaker — why would two of these wives ever do this in the first place? — was sorta answered in a realistically fuzzy way. And, while the show isn't shy about creating true villains, we at least saw hints of layered motive in the eviler characters, flashes of flaw and yearning and desire. It was the kind of satisfying, patient storytelling that HBO excels at. It just took Big Love three seasons to get there, rather than starting with a bang right out of the gate like The Sopranos.

If you're finding this review-type thing a little vague, that's deliberate. We don't want to give away any plot points in case you decide to go rent the DVDs and, bleary eyed and joyful, catch up in time for Sunday's premiere. Threads first glimpsed in the first season are suddenly brought up in the third. It's an immersive and loyalty-rewarding experience, so we don't really want to mention a single concrete detail.

What we will say is this: For our money, Big Love was the best thing on television last year. And we have high hopes for this go-around. Sissy Spacek's joining the cast! And, if nothing else, you just can't say no to Sissy Spacek, can you?