It's that smudge of fog called London under the reign of Victoria. When a music-hall dancer is murdered, a moss rose marks the page of a Bible next to her body. Luckily, another chorus girl (Peggy Cummins) saw a gentleman (Victor Mature) leaving the lodgings. She approaches him directly, saying she'll go to the police if he doesn't meet her demands, but he brushes her off contemptuously. When he learns she's dead serious, he tries to buy her off with a thick wad of pound notes. But it's not money she's after; all she wants is two weeks at his country estate, living the life of a `lady.'
And here Moss Rose, which has taken its time working up a head of steam, branches off onto a new siding. The estate contains not only Mature, his fiancée (Patricia Medina) and his formidable old dowager mother (Ethel Barrymore), but also a greenhouse where out-of-season moss roses bloom.
Apart from a few Eliza-Doolittle faux pas, the classes do not clash. Barrymore, in fact, extends Cummins a matey welcome; even Medina tries to put aside her understandable jealousy. The only apple of discord falls when Cummins strays innocently into Mature's boyhood rooms, which Barrymore preserves as a secret shrine.
Cummins finds the pastoral scene (`You'd expect to see a calendar pasted under it!' she exclaims) lives up to all her expectations. Thrown together, Mature has thawed markedly towards Cummins, and she towards him. But their idyll comes under siege with the arrival from London of bumbling Scotland Yard detective and amateur horticulturist Vincent Price, still investigating that pesky homicide. Soon there's another murder, another Bible, and another moss rose....
An old-dark-house costume drama akin to My Name Is Julia Ross or The Spiral Staircase, Moss Rose finds its strength in its actors rather than its direction (by Gregory Ratoff). While Mature stays four-square and Price unctuously fey, Barrymore predictably grande-dames it to the hilt. Cummins is lovely and quite good as a Cockney diamond-in-the-rough, but leaves nothing like the impression she would two years later as Annie Laurie Starr in Gun Crazy. An air of the contrived lingers after Moss Rose, more faded than pungent, but it's cozy and reassuring, too.
