August: Osage County, National Theatre (Lyttelton), London

You’ve met the Waltons and the Simpsons – now meet the Westons. Like many before him, the playwright Tracy Letts deploys family life to assess the health of America, and his diagnosis is not encouraging. The Westons, the family at the heart of Letts’ new play August: Osage County, take dysfunctional behaviour to spectacular levels. After huge success on Broadway, the play now rolls into London in a magnificent production by the Chicago Steppenwolf Company. And while the dramatic territory – family life as warfare – is far from new, Letts brings to it a mordant black humour that is both shocking and brilliant. You sit, aghast but glued, as the secrets and lies spill out in a dark, sticky torrent.