Shyamalan is naturally looking to keep the details quiet for now, in order not to spoil any potential surprises. But a brief plot nugget has leaked out, with word that Hahn will be a single mother who takes her son (Oxenbould) and daughter to visit their grandparents. What should be a happy family occasion goes horribly wrong.
If you were wondering, the title refers to a psychological phenomenon associated with increased confusion and restlessness in patients with some form of dementia, which can present with agitation and mood swings. From the sounds of it, this will be more than just an awkward visit to elderly relatives. Shyamalan has almost finished work on the film, which returns him to his lower budget horror roots. He's also preparing to make Labor Of Love, which reunites him with Bruce Willis.
Hahn, who will be on our screens next week in much-praised indie movie Afternoon Delight, also crops up in Jason Bateman's directorial debut Bad Words, which is in US cinemas but has yet to announce a UK release date.