Maxine worked in radio with her ex-husband, Max Wheeler, who became worried when his audience started disappearing one by one in 1955. They met Susan and the First Doctor, who were stuck in London because something was interfering with the TARDIS.
Max had served in World War II, and it turned out that an alien race that was used during the war were now causing both problems. Maxine and Max helped the Doctor and Susan defeat the aliens. (PROSE: Losing the Audience)