Catherine Tate's iconic character Nan hits the big screen as she goes on a wild road trip from London to Ireland with her grandson Jamie (Mathew Horne) to make amends with her estranged sister Nell (Katherine Parkinson).
With ruthless US and Japanese investment banks circling Tuftons, a struggling two-hundred-year-old, family-run British bank, can its bumbling, incompetent chairman, Sir Charles Bunbury, fend off the onslaught and save the bank?