“The Guernsey Literary and Potato Peel Pie Society” is an old-school, old-fashioned entertainment, a romantic drama bursting with scenic vistas and earnest charm that contains just enough mystery to keep us involved.

In fact, as efficiently directed by the veteran Mike Newell (“Four Weddings and a Funeral,” “Enchanted April”), this is just the kind of satisfying mainstream diversion that people used to leave their homes and go out to the movies for. Until now.

For though “Guernsey” has played quite successfully theatrically in Britain, France and other countries, in the U.S. Netflix acquired the distribution rights, and not even a token theatrical release in Los Angeles is in the works.

There is one sense, however, where “Guernsey,” adapted from the Mary Ann Shaffer and Annie Barrows’ best-selling novel by Thomas Bezucha, Kevin Hood and Don Roos, will look pleasantly familiar on home screens, and that is its cast.

No fewer than four actors, starting with star Lily James and including Jessica Brown Findlay, Matthew Goode and Penelope Wilton, had roles on PBS’ splendid “Downton Abbey” series.

James, fresh off facing off against Gary Oldman as Winston Churchill in “Darkest Hour” and playing a young Meryl Streep in “Mamma Mia! Here We Go Again,” is the undisputed star here, though brooding Dutch actor Michiel Huisman (“Game of Thrones”) gives her a run for her money as one of the most killingly handsome pig farmers in cinema history.

Though the film doesn’t let on, it’s helpful to know going in that the island of Guernsey, though officially a self-governing dependency of the British crown, is geographically closer to France than to Britain, which is why it was occupied by German troops during World War II, a key plot element.

James plays London writer Juliet Ashton, a sprightly woman introduced in 1946, just after the war has ended, riding a bus with her handsome publisher Sidney Stark (Goode). Ashton has just published a book, “Izzy Bickerstaff Goes to War,” written in that male character’s voice, and, eager to take on something in her own, she’s pleased but nervous when Stark tells her about an essay assignment from the London Times about the importance of reading.

Though there is tragedy in her background (her parents were killed during the Blitz), Ashton is determined to enjoy herself, and we see her dancing up a storm with a serious beau, wealthy American officer Mark Reynolds (Glen Powell).

One fateful day, Ashton gets a letter from Guernsey. It’s from Dawsey Adams, that knockout handsome pig farmer, who has come across her name and address in a used book. He introduces himself as a founding member of that Guernsey society, a book club actually, and innocently wonders if she could guide him to other books. Because audiences have already seen what a Heathcliff look-alike Adams is, we know where this story is going well before the characters themselves.