Los Angeles: Actors David Morrissey and Clemence Poesy have been cast in 'The Ones Below'.
Morrissey and the Poesy, best known for her role as Fleur Delacour in the 'Harry Potter' films, will feature in David Farr's directorial debut, reports suggest.
Stephen Campbell Moore ('The History Boys') and Laura Birn ('A Walk Among the Tombstones') will also star in the psychological thriller.
'The Ones Below' centres around two couples who live in upstairs and downstairs flats.
The neighbours are both expecting babies, but while the upstairs mother-to-be is nervous about the future, the downstairs neighbour's excitement hides a sinister secret.
British acting veteran Morrissey has recently been playing the Governor in AMC's comic book adaptation 'The Walking Dead'.
'The Ones Below' has begun shooting in London.