In the event that “The Sopranos” is an unfamiliar subject, please consider the following: a motivated viewer would only need two days to watch the 52 one-hour episodes that compose the first four seasons. And after that scholarly, pleasurable and very impressive viewing marathon, such a viewer would surely find comfort in the premiere of season five that aired last Sunday on HBO.

The year-and-a-half break between seasons gave a nightmarish quality to the explosive season-four finale. In all likelihood, had season five chosen to ignore the events of the fourth season completely, viewers would have assumed it was just a bad dream.

But writer David Chase is not quite ready to turn the lights on. Instead of glossing over the jagged turn of events introduced in “Whitecaps” (the 75-minute season-four finale), he chooses to emphasize the bizarre climate. Tony and Carmela are separated. Chase makes that clear in the opening sequence of the episode. The camera floats around the outside of the house, wondering the same exact thing as the viewer: “Shouldn’t Tony be in his bathrobe getting the paper?”

But it isn’t just Tony and Carmela that have changed. Who could explain Janice cooking Sunday-night dinner for her family? Or how about saint-like Bobby Bacala marrying the same woman who shot her fiancé in the chest? Something is rotten in the state of New Jersey.

While obvious changes call attention to themselves, season five also introduces many subtle differences that could be even more relevant. Paulie and Christopher’s rivalry began in season three, and they have both been fueling the fire ever since. The fight is reintroduced with a hint of irony.

As Chrisi narrates the episode at the Meadowlands, which just happens to be what started their fight, Paulie gets offended by Chrisi’s disrespectful mockery and almost hits him. However, all that hatred surprisingly dissipates and they forgive in each other. Despite what one might think, seeing those two badass mobsters make up is really quite heartwarming. Nevertheless, this truce may simply be an example of Chase’s mastery of misdirection.

Yes, Paulie and Chrisi finally seem to be getting along again, but do not forget that at the core of their fight is a power struggle. Will their friendship survive when Tony’s cousin is released from prison and joins the family?

The episode has an unusual structure. Seeing subplots intertwine on “The Sopranos” is as common as hearing Tony curse. More so, these unrelated storylines always tend to come to a climax at the same time and within the same scene.

In this episode, though, everything is given its own space and time. Every plot exists separately and every scene is given just one story. At the same time, however, a premiere requires that sort of structure because continuing stories need reintroduction and new plotlines require space to develop.

But that does not excuse the almost intentional absence of two important developments from season four. The assumption, then, is that it is that those two plots, which of course will remain secret, are going to be the most significant surprises that “The Sopranos” has in store for season five.