That he is able to take what is on the surface a standard-issue costume drama and make it truly engaging to the viewer speaks volumes about John Barrymore's screen presence and acting ability. This is amply demonstrated in When a Man Loves (1927), when would have been only a middle-of-the-road period picture without him. Certainly, the picture's production values are top-notch, from the Vitaphone orchestral soundtrack to the lavish costumes, but it's the unique energy that John Barrymore brings to the production that really makes it worth watching.
Originally based on the 1731 novel Manon Lescaut, the screenplay was substantially rewritten to make John Barrymore's Fabien des Grieux the primary focus of the story rather than Mlle. Lescaut herself, played by Dolores Costello in this screen adaptation. Perhaps as a result of this rewrite, Dolores is left without much to do in this picture beyond standing around in gaudy 18th century costumes looking crestfallen (although she admittedly does a pretty good job of this).
The picture begins with both Fabien and Manon on their way to join the life ecclesiastic -- Fabien is on the verge of joining the priesthood, while Manon is slated to be cloistered in a convent. These plans, as you might have imagined, quickly go awry. Fabien falls in love with Manon at first sight, symbolically dropping a pendant given to him to protect him from the temptations of the flesh. Manon, meanwhile, learns that her brother is plotting to sell her into prostitution (the evil brother is here played by Warner Oland, who always seems to play these sort of characters, Charlie Chan notwithstanding). Adventure ensues as Fabien and Manon escape to Paris together, and are separated and reunited time and again through a series of unfortunate twists of fate.
Throughout the picture, one cannot help but notice a recurring theme regarding Manon's virginity and the safeguarding thereof. That she is a virgin is established at the outset of the picture by the fact that she is en route to the nunnery. Shortly after that revelation, a kitten is shown hiding under Manon's skirts (throughout the early parts of the picture, Manon keeps this kitten tucked safely in a basket). Eventually, this kitten winds up in the care of Fabien, with instructions to "take very good care of Fifi!". It's extremely tempting to read this cat as a metaphor for ...well, a pussy of a very different sort. Furthermore, Fabien spends much of the film trying to keep a variety of unsavory characters from having their way with Manon (everyone from a Parisian guttersnipe to the captain of a prison ship to King Louis XV of France himself tries to get into Manon's petticoats).
That's taking care of Fifi for you. But let's get our minds out of the gutter.
Throughout all of this, it's John Barrymore who truly carries the picture. He gives the character of Fabien des Grieux an air of gravitas that few of his contemporaries could match, and plays the action scenes with a mania that makes the character significantly more likable than he might otherwise be (I imagine that des Grieux might seem a bit too noble if played by a matinee idol like Ramon Novarro). Whether fencing with French noblemen or leading an uprising on a prison ship bound for Louisiana, Barrymore's Fabien is zealous without being over the top. The rest of the acting is solid, even by the largely ornamental Dolores Costello, but When a Man Loves is undeniably John Barrymore's show.
It's a show worth watching if you get a chance.