Santos Casani and Jean Mence demonstrate the Crawl Charleston (or Charleston Blues) with Annette Mills at the piano.
Titles read: "Dancers of all degree are looking for a new dance - Today, Santos Casani, the famous Teacher of Ballroom Dancing (with Miss Jean Mence) will explain the Season's new dance. The Crawl Charleston (or Charleston Blues), at the piano - Annette Mills, Composer of the original music."
London (probably Pathe studio).
M/S of Santos Casani introducing the Crawl Charleston. He demonstrates the dance with Jean Mence (in a long dress) to the music played by Annette Mills at the piano. Intertitle explains "To demonstrate the footwork, we'll have to change Miss Mence's frock." M/S of Jean from the knees down, clad in the long dress fades into shot of her legs and feet and a shorter dress.
We then see several shots detailing the steps to this dance, including some taken from below a glass floor as Santos and Jean dance over it. M/S of Santos and Jean demonstrating the dance as before (Jean in long dress). Brief C/U of Annette Mills at the piano, playing energetically.
Intertitle gives the address of Pathe so people can write in for full printed details of the dance steps.
Note: this is presumably the Annette Mills of 'Muffin the Mule' fame, and sister of Sir John Mills.