NEW YORK (AP) – “The Sopranos” is back, and all is wrong with the world.

The TV drama every other drama series is measured against is returning to face the ultimate challenge: getting measured against its own past.

Great news! It measures up – especially after last season, which didn’t.

Last season, “The Sopranos” was gripped by tension. Week after week, the pressure built. As if resigned to inevitable doom, mobster Tony Soprano and everyone around him – and, to a large extent, the series – sank into a funk.

Sure, there were moments of explosive (if temporary) release. But just two of the 13 episodes delivered a solid dramatic payoff: when Tony offed Ralphie and then offed his head, and in the finale when Tony waged war with his wife, Carmela, and she threw him out of his house.

That was way back yonder in December 2002. Now, as “The Sopranos” begins its fifth season Sunday at 9 p.m. EST on HBO, it seems headed on a different, more rewarding track.

Spoiler warning: “Sopranos” fans who want a pristine viewing experience should stop reading here.

Make no mistake, any hour of “The Sopranos” beats an hour of nearly anything else on film. But the four new episodes made available for review do more than introduce fresh turmoil into Tony’s life. They introduce a welcome new theme enhancing last year’s gloom: a sense of general befuddlement.

Tony (series star James Gandolfini), his wife (Edie Falco), and other key characters have lost their bearings. Too much has changed, too much is uncertain. Can they regain their footing before it’s too late? That seems to be this season’s prevailing question.

One cause of shattered equilibrium is the arrival of several new mobsters who, jailed during the crackdown on organized crime in the 1980s, are out after serving their time.

“Class of 2004,” Uncle Junior (Dominic Chianese) sums up sourly – “old rats on a new ship.”

What will be the impact of these new “rats” on “The Sopranos”?

“We could be looking at a period of potentially violent power struggles,” declares a Mafia expert on a TV interview show Tony is watching – to which Tony grumbles, “They gotta paint everything the worst, these TV news people.”

It isn’t long before former mob boss Feech La Manna (Robert Loggia) is telling Tony, “Now that I’m out, I’d like to get back in the game.”

Tony warily agrees, but adds, “I don’t want you stepping on anybody’s toes.”

“Me?” oozes Feech in his gravelly voice, “I’m Fred Astaire.”

Also back on the streets (in the second episode) is a cousin, Tony Blundetto (played by Steve Buscemi), whom Soprano wants back in the family business.

No thanks, says “Tony B.” Once a rising star in the mob, he now intends to go straight.

He wants to be a massage therapist, and he doesn’t mean running a massage parlor. In the meantime, he takes a job with a linen supply firm whose accounts include the Bada Bing. He’s literally handling Tony’s dirty laundry. Will he be able to resist Tony’s entreaties to handle more?

The life of Tony’s nephew Christopher (Michael Imperioli) hangs in the balance: He’s kicked booze and drugs. But how long can he hold out?

And Christopher’s fiancee Adriana (Drea de Matteo) remains caught between a rock and a hard place: The FBI is forcing her to inform on Christopher and the rest of the mob. How long can she reconcile her two conflicting lives, not to mention her guilt?

Even Tony’s psychiatrist, Dr. Melfi (Lorraine Bracco), is confronting new issues, thanks to Tony, her longtime client who now wants to be more.

Sunday’s episode begins with a scene recalling previous season openers: the morning newspaper in the Soprano driveway. But Tony, no longer living there, isn’t fetching it.

A bit later, the series adds to its gallery of odd and powerful images with a glimpse of raw potential violence that is all the more unexpected for its having no connection with organized crime.

Message: More than ever before, everything is on the loose, and danger could be lurking anywhere.

No wonder Tony – who now bunks in, of all places, the shabby house of his despicable late mother – drifts back home on any pretext. There he scraps with Carmela, barks at sullen son A.J. (Robert Iler), chugs orange juice out of the carton as if he still ruled the roost, and pretends none of the fault is his.

It’s all part of a scramble for some sense of normality, for getting back a world that’s familiar and reliable. Happily for viewers, the search on “The Sopranos” this season could come with many new pitfalls.