Vicar Rowan Atkinson and his troubled family - wife Kristin Scott Thomas, nympho daughter Tamsin Egerton and bullied schoolboy Toby Parkes - need help. They get it from housekeeper Maggie Smith, who, in order to keep the family together, delivers cheery wisdom and brutal murders in equal proportions. It could have been a cross between Mary Poppins and Kind Hearts And Coronets. That the end result is like an episode of The Vicar Of Dibley with added corpses is purely down to a lack of conviction. Writer/director Niall Johnson is blessed with a decent cast, but he can't decide what kind of film he wants them to be in. Slapstick, sex comedy, feelgood fun... if he'd picked one, Keeping Mum might have been fine. As it is, there's an uncertain, fumbling quality to it all, with the tone of one scene undercutting the next until your patience is shredded. Dumb, not mum, is the word.