In the years since Karina Longworth launched You Must Remember This, a podcast about forgotten Hollywood stories, her focus has been eclectic, moving from stars such as Marlene Dietrich, Audrey Hepburn, Elizabeth Taylor, and Barbra Streisand to the Jewish mobster Bugsy Siegel and Hollywood’s first weight-loss guru, Madame Sylvia. There have been seasons devoted to Charles Manson’s Hollywood, to the hit TV series Babylon Berlin, and to “Dead Blondes”—which included Jean Harlow, Grace Kelly, Veronica Lake, Jayne Mansfield, and Marilyn Monroe. The latest season, titled “Gossip Girls,” looks at the American newspaper columnists Louella Parsons and Hedda Hopper, who at their peaks had a combined readership of 55 million. —J.V.