Heading back to Downton

Michelle Dockery as Lady Mary and Allen Leech as Tom Branson in 'Downton Abbey'.

The audience are hungry for answers this season, writes Sarah Lang

Downton Abbey, the period drama that needs no introduction, is my comfort food. It reminds me of the roast dinners of my childhood: warm, familiar and never rushed. The fourth season of the British hit premieres on Prime tomorrow night, and I'm curious to see where the show will go now that it is back on form.

After the soap-opera histrionics of its second series - imposter heirs and paralysed soldiers leaping to their feet - critics scolded the show like Carson (Jim Carter) scolds his footmen. But in Series Three Downton returned to what it does best: character-led drama, drawing-room comedy and social commentary that highlight the bonds and the divides between upstairs and downstairs in a rapidly changing world.

The third season centred on the choice between adaptation or extinction in an England forever altered by war. Even "poor old Edith" (Laura Carmichael) began to have her say and do things her way, while Robert (Hugh Bonneville) stubbornly clung to the past, taking every call for change as a personal insult. Then again, stuffy old Robert wasn't fazed by Thomas (Rob James-Collier) being gay, while the gruffly likable Carson had a homophobic rant. Did anyone else feel sorry for Thomas for a nanosecond?

In the series finale, the family holidayed in Scotland, where Edith's editor Gregson (Charles Edwards) just happened to be in the neighbourhood, and Robert found a new appreciation for his marriage - and for Matthew's (Dan Stevens) efforts to modernise the estate. Returning home early, Mary (Michelle Dockery) gave birth to George, heir to Downton. But one can't end a season on such a happy note, can one? Just after meeting his son in the Christmas special Matthew dies in a car crash. I thought Sybil (Jessica Brown Findlay) dying was enough young life lost for one season, but Stevens quit and the writers reportedly couldn't bear to break up their golden couple.

The fourth series picks up in 1922, six months after Matthew's death. I won't give too much away, but the first episode is a cracker. It opens with an unidentified woman sneaking out of Downton in the small hours, and focuses on the grief over Matthew's death. The death of her only child has broken Isobel (Penelope Wilton), and we can read Mary's pain in her eyes. As Mary's family tries to help her, the Dowager Countess (Dame Maggie Smith) foregoes her usual barbed quips and raised eyebrows to speak from the heart - something that is all the more powerful for being so rare. Gosh, Maggie Smith is good.

Injecting some glamour and optimism are scenes set among the London literati, as Edith meets with Gregson. Who would have thought the plain, overlooked sister jilted at the altar would become a modern career woman with self-confidence, style and an admirer?

Expect the spotlight to be firmly fixed on social change amid the new freedoms of the Roaring Twenties. How far will Edith go for love? Will Mary find meaning in life again? What mischief will cousin Rose get up to? Will Tom stay or go? Has Thomas reformed? Will the maids and footmen ever unravel their love quadrangle? Will Mrs Patmore master the electric beater? And why does Kiri Te Kanawa randomly pop up playing a famous soprano? I'm trying to avoid reading spoilers, so my appetite for Downton is definitely back.