An unidentified man on an unidentified beach sees an unidentified light. Then there are sewn-together lips. So goes the minute of video posted to the YouTube channel of J.J. Abrams’s Bad Robot Productions. The video, called simply “Stranger,” is a bit of viral advertising for one of Abrams’s many upcoming projects. What project that may be remains a mystery, but many are speculating the video is a teaser for his upcoming novel. S. A Novel, to be released in October, is the first book by the filmmaker, written in collaboration with author Doug Dorst. In typical Abrams fashion, the cover has yet to be revealed and the plot remains a secret. However, “Stranger” may be a first look at it. Or maybe it’s an ad for Star Wars.