Written by Julian Fellowes, who brought us Downton Abbey and recent series The Gilded Age, and directed by Michael Engler, who worked on both the aforementioned, this based-extremely-loosely-on-fact costume drama adapted from a novel by Laura Moriarty should hit the sweet spot for fans of Fellowes’ particular variety of saucy-soapy period pieces. Like so much of Fellowes’ work, it effectively flatters the viewer by assuming he or she must be familiar with certain historical figures (in this case, early cinema star Louise Brooks) and then appears to dish the dirt on them through the eyes of a character from another class or at least different social sphere.

Here, that parallax view is from the perspective of Norma – played by Lady Grantham herself, Elizabeth McGovern, taking a lead role for a change. When first met in 1922 in Wichita, Kansas, Norma seems like a nice, churchgoing lady of a certain age, respectably married to a lawyer (Campbell Scott) and mother of two practically grownup sons. When she hears that local pianist Myra Brooks (Victoria Hill) is in search of a chaperone to accompany her precocious but exceedingly talented teenage daughter Louise (Haley Lu Richardson) to New York to attend a prestigious dance school, Norma mysteriously jumps at the chance. Turns out she has a good reason: she was actually raised in an orphanage there for a short while before being adopted by kindly midwestern farmers, and now wants to find her birth parents.

However, Louise is a bit of a handful, as anyone who knows a bit about the real Louise Brooks would be aware. Beyond the plot frame of the film, she went on to become a actor in such films as Pandora’s Box (1929), as well as a hot mess later in life, but at this stage she’s just a headstrong, naturally unconventional kid with incandescent talent and huge ambition. Turns out the chaperoning gig is harder than it looks; Louise is forever sneaking off to do whatever she wants.

Richardson has a super-silky, immaculately-cut black bob to fill in playing a character as iconic as Brooks; otherwise she is about 80% there in terms of charisma and dancing skills, and around 70% when it comes to the sex appeal and feral intelligence – but in truth it would be a challenge for anyone. McGovern holds her own gracefully, especially when Norma discovers a side to herself she didn’t know was there when she meets a handsome German handyman (Géza Röhrig) at her old orphanage, a sensitive arthouse stud-monkey if ever there was one. All the corny romance stuff is about as intrinsic to the film’s soft appeal as the scrupulously well-made frocks, encompassing late Edwardian lace and flapper-style dropwaist numbers, and dozens of well-turned cloche hats.

• The Chaperone is released on 21 February on digital platforms.