Starring Domhnall Gleeson. Rated PG

Goodbye Christopher Robin seems to be at odds with itself. On one hand, it’s just as Masterpiece Theatre twee as you’d expect from a British-made period piece about famous people. On the other, it has a darkly subversive streak regarding unpleasant human behaviours—the kind that haven’t exactly disappeared over the last hundred years.

The story, if not the movie structure itself, begins that long ago, with the twentysomething A.A. Milne (played superbly throughout by Domhnall Gleeson) caught in the terrifying trench combat of what was then called the War to End All Wars. Good branding; horrible lie. He returns to upper-crust London life, in which PTSD–suffering veterans can just about allow themselves quick nods to that “bad show” in the blood-soaked fields of France. Milne was already an established writer of light plays and Punch magazine satire. Postwar life didn’t call for such frivolity, but you can imagine how eager English publishers were to spend money on angry tracts about arms merchants and corrupt aristocrats.

Keeping the coffers full was very important to his fashion-plate wife, Daphne. (She actually looked more like Flora Robson than Margot Robbie, but only the latter was available.) So Milne, nicknamed Blue, attempted to rediscover his writing voice by moving out to the quiet countryside of East Sussex, from where Daphne frequently decamped back to the flapper-mad capital, leaving small son Christopher Robin (mostly played by engaging eight-year-old Will Tilston) with a caring nanny (Kelly Macdonald) and an initially indifferent dad.

Of course, ol’ Blue eventually became entranced by the fantasy world created by the boy, called Billy at home, based on stuffed animals his mother brought him from town. These included, oh, let’s see: a tiger, a piglet, a donkey, and a brown bear named after a regal creature sent to the London Zoo from Winnipeg.

Directed by Simon Curtis, responsible for such middlebrow, reality-based affairs as The Woman in Gold and My Summer With Marilyn, the new movie compresses years of Winnie-the-Pooh bestsellers into a kind of golden summer of father-son rapprochement. Christopher Milne’s memoirs suggest that the upper lips stayed pretty stiff for the rest of their lives. Certainly, there’s some perfectly horrid parenting on display here from the beginning. The first hour is filmed with light so honeyed (or hunnyed, for Pooh fans) and enough Disney-esque effects that it comes as quite a gut punch when Winnie’s worldwide success plunges the boy with the Buster Brown bowl cut into a more or less permanent nightmare. Family fare it ain’t, but if you’re open to its mood swings, this Goodbye has something complicated to say to the hurt children we used to be.