“Downton Abbey,” the phenomenally successful British period drama series created and written by Julian Fellowes, begins its second season on PBS tonight. By the time it ends on February 19, its legions of fans will have wolfed down 10 fresh hours of what the historian A.N. Wilson has disparagingly described as sanitized escapist fantasy.

When the four 90-minute episodes of season one aired in the U.S. a year ago they chalked up a nightly average of 4.9 million viewers (in contrast to a 1.9 million average for PBS according to Nielsen). The Masterpiece Theater publicists have been giving season two the big push, and the chances of its audience topping 5 million are high. U.K. viewing figures rose from just over 9 million for season one to 11.71 million for season two, which aired in the fall. (The figure for the two-hour Christmas Day special was 11.59 million.) That means over one in five British people are regular viewers.

In the first series, the aristocratic Crawley family’s succession crisis was caused by the loss of its two male heirs on the Titanic. This time there are two sources of consternation, first the Great War, then the 1918-19 Spanish flu epidemic. As in season one, the main narrative strands are (1) the torturously blocked love affair of Lady Mary (Michelle Dockery), the Earl of Grantham’s eldest daughter, and Matthew Crawley (Dan Stevens), the current heir and now an army captain; (2) the torturously blocked love affair of Anna Smith (Joanne Froggatt), Mary’s maid, and John Bates (Brendan Coyle), the earl’s valet-with-a-past.

The earl himself, Robert Crawley (Hugh Bonneville), is in a snit because the army deems him too old to fight and, in the last episode, he acts out in a most unbecoming manner; his wife, the American Countess Cora (Elizabeth McGovern), is still woefully naïve but determined not to be bossed around by Matthew’s mother, Isobel (Penelope Wilton), when Downton is turned into a military hospital under her supervision. Mary’s sisters, Lady Sybil (the pretty one, now a nurse), and Lady Edith (the peevish one, briefly a farm worker) shamelessly become involved with men beneath their station. O’Brien, the Machiavellian ladies’ maid, and Thomas, the disaffected footman, are up to their old tricks.

And the Dowager is busy disapproving of everyone’s best-laid plans with raisings of eyebrows and twitchings of mouth — primarily because she is played by Maggie Smith. The Yorkshire house (actually Highclere Castle in Berkshire) and its grounds look lovelier and more expensive to maintain than ever, the trenches of the Western Front, where Captain Crawley and second footman William meet up, are even more art-directed. The only secrets I will reveal are that at least two characters are caught in flagrante delicto and that poor Carson the butler (who’s not one of them) nearly collapses on His Lordship’s dinner table from a different kind of exertion.

Thus, if you love sumptuously produced country-house melodrama involving glorious vistas, fabulous décor and clothes, high-strung romances and tons of simmering sexual frustration above and below stairs, the illicit thrill of cross-class canoodlings, the pluck and derring-do of officer types, and the dastardly doings of ungrateful servants (the Machiavellian lady’s maid, the malcontent footman, the Irish rebel chauffeur), then tune in and enjoy – you won’t be disappointed.

If, however, you’re turned off by the right-wing values of British heritage drama in its full “Brideshead”-ian pomp, the showcasing of class inequality (the Crawleys are privileged not only socially but in terms of their facility for achieving happiness), and the idea that the drudges  are most likely to be spiteful, malevolent and, yes, murderous, then “Downton Abbey” is not for you. (The one anti-establishment character, the chauffeur, turns out to be a mockery of an IRA assassin.) In this respect, the show differs from the legendary “Upstairs Downstairs” (1971-75, U.K.; 1974-77, U.S.), which favored the fortunes of the essentially decent below-stairs characters over the more decadent Bellamy family (Sir Richard excepted).

Certainly problematic are “Downton Abbey”’s privileging of plot over characterization, the absence of directorial personality, and the startlingly old-fashioned stiff-upper-lip or fatalistic nonsense that issues from the characters’ mouths. Although the "good" characters are typically flawed and the meanest of them capable of compassion, there is a marked lack of psychological depth. The Earl, the Countess, and the Dowager are notably two-dimensional, though that didn’t stop the Hollywood Foreign Press Association nominating Bonneville, McGovern, and Smith for Golden Globes for their work in the first series, which was nominated as Best Miniseries or TV Movie. There is, in addition, an implausible quality to the second series, particularly in terms of  various Crawleys’ hobnobbing with the help and the frequency of cross-class sexual dalliances—one wouldn’t be surprised if Daisy the hapless scullery maid put the moves on the dashing blond captain (she doesn’t).

The British critics mostly praised season two, though some were bemused by its wayward narrative. “The sense that the outwardly stately ‘Downton Abbey’ was being thrown together in a panic gathered pace as the series progressed, with bundles of new storylines being flung desperately into the boilers to keep the show on the road rather than continuing series one's more measured exploration of character and motivation,” wrote Adam Sweeting of theartsdesk.com. Commenting on its lack of authenticity, Wilson (author of “After the Victorians”) went for the jugular, accusing Lord Fellowes of glorifying “an ordering of society that was hateful in reality. While the real life aristocracy of Edwardian England lived in grandeur and expected other people to wait on them and attend to all their needs, the great majority of British people lived without sanitation, education or comfort.”

It might be argued that the squalid, poverty-stricken world Wilson speaks of in his sustained attacks on “Downton Abbey” is not the stuff of high-end miniseries. But that isn’t quite the case. Last year’s neo-Gothic BBC four-parter “The Crimson Petal and the White,” adapted by Lucinda Coxon from Michael Faber’s post=Dickensian novel and directed by Marc Munden, depicted the misery, terror and degradation that was the lot of London street prostitutes in the Victorian era. Still to be broadcast here, “Crimson Petal” is far superior to “Downton Abbey” and — the opposite of comforting — far less marketable.

While I agree with Wilson that “Downton Abbey” presents a class-obsessed Neverland, one through which Lady Mary and Captain Crawley stroll like star-crossed young gods, I'm not immune to its fiendish seductiveness. At a low ebb in the new series, the war-weary Downton-ites get up a morale-boosting show for everyone in the house and Mary and Edith cease hostilities to duet on the 1916 hit “If You Were the Only Girl (in the World).” Before the song ends something happens (of class-transcending import) that, when I saw it, sent shivers up my spine.  It’s nothing if not a great soap — and season three is in the works.