Few would dispute the supremacy of Cranford and Lark Rise to Candleford among the BBC’s current fleet of costume dramas. Measured, domestic and infinitely gentle, there are no Machiavellian footmen or illicit trysts here, just wholesome country adventures championing those unfashionable values of honesty, neighbourliness and hard work. The lamentable histrionics of the recent Upstairs Downstairs could have done well to note these successes, adapting material free from obvious drama (and in the case of Flora Thompson’s autobiographical trilogy, almost entirely without plot) and fashioning from it something credible and engaging. Lark Rise has its saccharine-sincere faults, but there’s no denying that with its characters back in the Sunday-night television slot, all somehow feels right with the world again.

If there’s one thing the British love on television at Christmas time, it’s a period drama, and even better, a period mystery. So what joy when there’s a bit of sleuthing by Agatha Christie's yin to Hercule Poirot’s yang, the eagle-eyed wise old bird Miss Marple, in The Secret of Chimneys.

Miss Marple (Julia McKenzie) is asked by Lady Virginia Revel (Charlotte Salt), the daughter of a dead cousin (what a lot of those the old girl appears to have), to be part of a lavish weekend party at the family’s country pile, Chimneys. The house was once known for its society gatherings until a rare diamond was stolen at a party in 1932, a theft that led to the end of Virginia’s diplomat father’s (Edward Fox) career.

The action starts 23 years on, when the world has changed and Chimneys is now too expensive for the family to maintain, but the ambitious and very dull politician George Lomax (Adam Godley) has offered to save it if Virginia, by some years his junior, accepts his proposal of marriage. Trouble is, she has just met and fallen in love with the dashing young Anthony Cade (Jonas Armstrong).

This being Agatha Christie (or at least a very loose adaptation, as she never appeared in the original story), those aren’t enough strands for us to unravel when someone is found deaded, in this case a mysterious Austrian Count (Anthony Higgins) who has specifically asked for a major international trade deal brokered by Lomax to be signed at Chimneys. There’s the chippy Miss Blenkinsopp (Ruth Jones), for one, from the newly created National Heritage who is very keen to get her hands on the property and is found snooping in the library; civil servant Bill Eversleigh (Mathew Horne), another would-be lover of Virginia; Virginia’s unmarried older sister, Bundle (Dervla Kirwan); and the family servant, Tredwell (Michelle Collins), who, Miss Marple soon realises, Has A Secret.

Chief Inspector Battle (Stephen Dillane) arrives from Scotland Yard to investigate and enlists Miss Marple’s help, but then two more deaths occur and lots of red herrings are released into this particular pond. The complicated plot includes a cache of love letters, coded messages, the cover-up of a death long ago and not one but two people with gambling debts.

As we eventually find the dastardly murderer, it all adds up to some nice light entertainment, of course, but by golly I wish everyone involved in The Secret of Chimneys could have given it even the faintest whiff of urgency. The feature-length episode was wonderful to look at, but I’m afraid both Poirot and Marple mysteries on ITV now appear to have taken over from The Bill as the common entry on all British actors' CVs; nice little earners where they galumph about pretty locations and spout trite dialogue as they wait either to be bumped orf or reveal the reason they committed the murder.

Few actors in The Secret of Chimneys appeared to have invested even a minimal effort in their characterisations. Edward Fox, we all know, has been playing variations on his most famous role, the Duke of Windsor, for some time now (the BBC missed a trick in not asking him to appear in the updated Upstairs Downstairs, set in the mid 1930s), Charlotte Salt’s accent was nowhere near posh enough (in contrast to Dervla Kirwan’s spot-on "frightfully"), Michelle Collins was miscast and, fine actress though she is, I think Julia McKenzie is too young and sprightly for Miss Marple.

Perhaps I spent too much of my youth reading Agatha Christie, but I remember her books being page turners; here the story dragged and by the end I didn’t care who had bumped off the Count. Full marks to the location, wardrobe and make-up people, however, as not a cuff or coiffure was out of place.

Thirty-five years after Rose Buck took what she thought was her final nostalgic stroll through the empty rooms of 165 Eaton Place in Belgravia, where she had served the Bellamy family for four decades, Jean Marsh has brought Rose back home in the BBC’s three-part remake of Upstairs Downstairs. Also aboard for this much-anticipated revival is Eileen Atkins, who was Marsh’s co-creator of the original version for LWT but was prevented by stage commitments from appearing in it. They were going to call it Behind the Green Baize Door and then Below Stairs before the familiar title was finally settled upon.

It was an awkward brief - create a series which captures the spirit of the original while being a separate creation with its own characters and identity – but this opening episode of three hove into view confidently enough (on board an ocean liner from New York, in fact). The year was 1936, and Sir Hallam and Lady Agnes Holland were returning from America to take up residence in the house that Hallam had inherited from his father.

Its address was of course 165 Eaton Place, which had fallen into a ruinous state but was soon in the throes of energetic refurbishment, bossily supervised by Keeley Hawes’s imperious Lady Agnes. She was quickly issuing lists of demands to Rose, who was now running Buck’s of Belgravia, an agency supplying domestic staff to the Quality, but no ESP was required to predict that the imperishable elastic of destiny was about to twang her back below stairs at number 165.

Being preceded by the remarkable success of ITV’s Downton Abbey is probably a mixed blessing. Downton has vividly demonstrated an appetite for period dramas with a class-war subtext and a pre-war setting (different war, but you get my drift), and has left swathes of viewers gasping for more startling liaisons, seven-course dinners and caustic one-liners from Maggie Smith (or insert dowager-esque equivalent). However, so far you’d have to say that the Downton cast has more strength in depth, and the piece also benefited from the mischievous and ironic wit of its creator Julian Fellowes (Eileen Atkins as Lady Maud, pictured below).

This first episode of Upstairs Downstairs felt bogged down with exposition and scene-setting, and despite a hyperactive subplot featuring Ivy the housemaid and Johnny the inebriate footman, it walked blithely into the Momentous Events from History trap which recently hamstrung Any Human Heart. This may be a result of the timorous decision to make only an exploratory three episodes, causing everything to be crammed in and speeded up. In this first hour, we learned of the death of King George V, with Rose taking the opportunity while queueing to view the lying-in-state to persuade Mrs Thackeray (Anne Reid) to accept the post of cook in the Holland household. We had the accession of flaky Edward VIII, gossip about that brassy Mrs Simpson, Hitler ranting on the wireless, and a warning from Foreign Secretary Anthony Eden to Sir Hallam (Ed Stoppard, rendered virtually immobile by starch and Brylcreem) about that bounder von Ribbentrop, in London to whip up support for the Nazis. It was like a Coles Notes summary of the path to World War Two.

Thank heavens for Dame Eileen, playing Hallam’s feisty and eccentric mother Lady Maud, who had returned from decades of colonial service in India accompanied by a precocious pet monkey and a manservant, Mr Amanjit (Art Malik, verging on the ludicrous in beard and turban). Hallam, who’s a bit wishy-washy, like one of Bertie Wooster’s daft chums from the Drones Club, has found himself caught in a titanic clash of wills between Lady Maud and his wife. When Maud airily rewrote both the menu and the guest list for Lady Agnes’s cocktail party, there was almost an ahistorical outbreak of nuclear war when her invitee Wallis Simpson (Emma Clifford) swept through the front door, accompanied not by the anticipated King Edward, but by the supercilious von Ribbentrop (Edward Baker-Duly).

It took quick thinking by the dyspeptic butler Mr Pritchard (Adrian Scarborough) to effect the speedy egress of the Boche from the premises. But I don’t think Lady Agnes would really have bellowed “Perhaps you’ll let me choose my own guests next time” across a room full of politicians and aristocrats at her mother-in-law, do you?

All good fun, but this mini-series will be over by tomorrow night. We may have to wait for a full-length run before Upstairs Downstairs II can really prove its mettle.

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THE MANY SIDES OF KEELEY HAWES, DRAMA QUEEN

Ambassadors, BBC Two. Mitchell and Webb and Hawes pack their bags for Tazbekistan to star in a diplomatic comedy drama

Ashes to Ashes, BBC One. Hawes’s Eighties copper goes back to the future in Ashley Pharaoh’s follow-up to Life on Mars

Identity, ITV1. Keeley Hawes and Aidan Gillen on the trail of ruthless cyber-criminals

Line of Duty, BBC Two. Gruelling police corruption thriller keeps spines tingling to the end.

The Casual Vacancy, BBC One. Hawes peddles erotica in JK Rowling's Cotswold village

The Hollow Crown: The Wars of the Roses - Richard III, BBC Two. Hawes’s first stab at iambic pentameter opposite Benedict Cumberbatch chilly crook-backed king

The Missing, BBC One. Hawes plays a grieving mother in misery-drenched odyssey

OVERLEAF: CLAIRE FOY’S CV