The Girl Up-stairs had quite a miscellaneous lot of plot; indeed a plot fancier might have detected nearly all the famous strains in its lineage. Its foci were Sylvia Huntington, the beautiful multi-millionairess, and Richard Benham, nephew of Minim, the Cosmetic King and head of the Talcum Trust. Sylvia, tired of being sought for her wealth, and yearning to be loved for herself alone, has run away to Bohemia and installed herself in an attic over a studio occupied by two penniless artists, one a poet, the other a musician. Only they aren't penniless any more, having leaped to wealth and fame with an immensely successful musical comedy they have just written. And, like Nanki Poo, the musician isn't really a musician, but is the talented, rebellious nephew of the Cosmetic King, none other than Dick Benham himself, a truant from his tyrannical uncle's determination to make him into a rouge and talcum salesman. He falls in love with Sylvia, not knowing her as Sylvia, of course, but only as the girl up-stairs, a poor little wretch to whom in the goodness of his heart, he is giving singing lessons. And she falls in love with him, knowing him neither as Dick Benham, nor as the successful composer (because his authorship of the musical comedy has been kept a secret from her), but only as a poor struggling musician. Poor Dick's affections are temporarily led astray by the mercenary seductions of the leading lady in his opera, who has learned the secret of his true identity and vast wealth, and means to marry him under the cloak of disinterested affection. He gets bad advice from his poet friend, too, who has dishonorable designs on the girl up-stairs and so warns Dick against throwing himself away on a nobody, of, possibly, doubtful virtue. It is, of course, essential to Sylvia that Dick should ask her to marry him before he learns who she really is, in order that she may be sure it isn't for her wealth that he is seeking her. This was the general lie of the land, though the thing was complicated, of course, by minor intrigues, as for instance in the first act, when Minim, the uncle, came to inquire of the successful composer what his terms would be for introducing a song into his opera, extolling the merits of Minim's newest brand of liquid face-powder. Then there was the comic detective, whom Sylvia's frantic father had given the job of finding her, and who, considering that he was the typical idiot detective of musical comedy, came unaccountably close to doing it.