SPOILER ALERT if you haven’t watched Sunday’s episode yet, crawl back in your coffin.

Trueblood10_06 The third-season finale of HBO’s “True Blood”drew lusty ratings — an estimated 5.4 million viewers for the initial Sunday run, despite formidable competition — but also laid bare some of the problems with the current season creatively.

Adding werewolves turned out to possess less bite than anticipated, mostly because the furry bastards weren’t very interesting. And the plots involving the supporting players proved wildly uneven, putting most of the weight on the Bill-Eric-Sookie not-quite triangle and the vampire power struggle with the King of Mississippi, niftily played by Dennis O’Hare.

Still, the resolution of that conflict — with O’Hare’s snarling vampire getting buried in cement, after eviscerating a TV anchor in an earlier episode on live television — wasn’t wholly satisfying, and the cliffhanger wasn’t one of the show’s best.

So next year, witches and faeries? Woo-hoo.

“True Blood” has nevertheless become a huge hit by HBO’s standards, with one executive at another network calling it possibly the most valuable franchise in TV right now because of its cultish audience and various tie-ins. It’s still fun to watch, but is currently riding a wave of hype and heat from the cast without being creatively consistent enough for my taste.

Fortunately for HBO, the finale marks the baton pass to “Boardwalk Empire,” which I have already drooled all over, along with a number of other critics. And given the way that HBO keeps score, all that saliva might be worth its weight in gold, if not blood.