The story follows a single mother (Kathryn Hahn) whose young children visit their grandparents, and things go horribly wrong. Ed Oxenbould plays one of the children, who is very protective of his sister. No other plot details have been revealed, but the title alone could offer some clues. The term Sundowning is a "psychological phenomenon" with symptoms that include restlessness and increased confusion in patients who have dementia, along with agitation and mood swings.
M. Night Shyamalan is directing from his own script and producing alongside Marc Bienstock and Ashwin Rajan, with Steven Schneider executive producing. Production has nearly wrapped in the filmmaker's hometown of Philadelphia, on what is described as a low budget.
Kathryn Hahn can currently be seen in Jason Bateman's directorial debut Bad Words, and she will next be seen in This Is Where I Leave You and Tomorrowland. Ed Oxenbould stars in the upcoming Alexander and the Terrible, Horrible, No Good, Very Bad Day.