Sunday night on BBC One is the cosy-blanket-and-Horlicks slot, a time when audiences don’t expect to witness anything much more traumatic than Judi Dench’s bonnet falling into a puddle or Minty from Eastenders opening a tin of fusty spam. How, without causing indigestion, can a main course dealing in the profound horror and loss of WWI follow on from an Antiques Roadshow starter and Countryfile amuse-bouche? There’s the odd pantomimic character of course; it wouldn’t be a First World War drama without a heartless toff riding roughshod over the troops. Colonel Purbright (boo hiss) fulfils this role, a one-man ATOS who judges anyone who can walk a straight line fit for battle regardless of what a shivering, addled wreck the front line has made them. Lance Corporal Prentiss’ story wasn’t only an affecting reminder of the paucity of understanding of mental illness at the beginning of the last century, but also a useful touchstone to introduce the other characters’ compassion. We now know that Colonel Purbright and cake-thieving, axe-grinding Sister Quayle are pragmatic at best and cruel at worst, while Matron Carter and Lieutenant-Colonel Brett (Mr Molesley to Downton fans) both have a heart. The former may have disguised hers to impress the former mentor she leapfrogged to promotion, but the Matron’s tenderness was evident from the episode’s first to last moments. The three volunteers arrive with emotional baggage inversely proportional to their actual luggage (our Kitty walks in swinging a matchbox of possessions, while Fruitcake Flora struggles with a trunk the girth of Wales). No sooner has the trio been marched past trolleys of amputated limbs and fly-ridden surgical tents than they’re set to work on the bed-making round on The Generation Game. At this and other indignities, Kitty balks, though she has the mettle to stand up not only to the patronising attention of a ‘dashing’ Captain, but also to a patient with evil literally dribbling out of him who threatens to cut her whore’s throat with a pair of surgical scissors. Choosing to nurse her attacker gently through his death showed Kitty to be of a mind with Matron, who had declared somewhat stodgily earlier that “All men deserve the same when they’re dying, no matter what they’re said to have done”. The Crimson Field tempers frilliness with grimness – sometimes, as Flora’s teacup of toes showed us, in the same scene. Creating a WWI drama light enough to entertain with comedy and romance (Kitty and handsome Scottish Captain Gillan are surely heading for a clinch) that doesn’t whitewash the utter human degradation of the First World War is no mean feat, but at this early stage, it seems Phelps and co. have managed it. Bravo. Follow our Twitter feed for faster news and bad jokes right here. And be our Facebook chum here.