The Madame Blanc Mysteries (C5)Rating:(Four out of five stars)Marlene and the bare-bottomed window cleaner. Or, looking at it the other way around, the wife of dodgy car dealer Boycie and cinema’s sauciest driving instructor. What a pairing.Sue Holderness (from Only Fools And Horses) and Robin Askwith (he of the Confessions movies), reunited as The Madame Blanc Mysteries returned for a fifth season, must be the most disreputable couple in the cosy crime universe.She flirts ferociously with any man in possession of his own teeth. He has a face like a sponge cake that’s been steeped in brandy overnight.Where expat toffs Judith and Jeremy get their money is a mystery in itself, though the way he never contradicts her makes me suspect the cash is chiefly stashed in her savings accounts.Between them they seem to own half the village of Sainte Victoire in the South of France – the wine bar La Couronne, a chateau with extensive gardens and, as Judith casually let slip, several ‘summer residences’.Originally they were cameo characters, but they’re such fun that writers and co-stars Sally Lindsay and Sue Vincent can’t resist bringing them front and centre. Steve Edge, who plays hangdog taxi driver Dom, is no longer just the sidekick either. His role as romantic lead and single dad has propelled him into the foreground. Sue Holderness (from Only Fools And Horses) and Robin Askwith (he of the Confessions movies), reunited as The Madame Blanc Mysteries returned for a fifth season, must be the most disreputable couple in the cosy crime universeAnd then there’s Sir Tony Robinson as Dom’s seedy Uncle Patrick, a small-time crook who was absent from this opening episode but is promised to return.The problem is that, as the background figures grow, they’re pushing the main character out of the frame. Lindsay, as antiques dealer Jean White, is meant to be the star, but she doesn’t have much to do except take notes as the spotlight switches from one murder suspect to another.When the series first aired in 2021, it had a unique concept that helped it stand apart from other slayed-in-the-sunshine set-ups. Jean’s expertise in brocante, the world of second-hand treasures from Regence furniture to Resistance medals, helped her decode the clues scattered in the bric-a-brac of the victim’s homes.It’s a neat conceit. But her character has faded almost to the point of invisibility. Instead of concentrating on her eccentric friends, the show needs to discover new things about Jean herself. One way to do that might be to develop her friendship with the local police inspector, Gendarme Caron. He relies heavily on her expertise, but we never see them together unless they’re discussing a case or interrogating a witness.The show also needs to be careful to avoid overt violence. This time, we saw a woman savagely stabbed to death by a masked figure. That should have happened off camera.Why am I being so critical? Because Madame Blanc is one of my favourite cosies. If it can keep the right balance, it ought to run forever. Judith and Jeremy will certainly drink to that.