American film star Florence Turner is Alone in London in this 4-reel British mystery. Turner goes against the grain of her established screen image by playing a meaty character role as a woman inexorably involved in crime. Henry Edwards co-stars as one of the "good guys," while Edward Lingard represents the "bad" contingent. Ms. Turner, the onetime "Vitagraph Girl," was herself the producer of Alone in London; it was the last in a successful series of British productions financed by Ms. Turner in conjunction with England's pioneer filmmaker Cecil M. Hepworth. The director was Larry Trimble, Turner's lifelong friend. Alone in London was based on a play by Harriet Jay and Robert Buchanan, which presumably ran longer than the film's allotted 48 minutes.