Last night's viewing - Monroe, ITV1; New Tricks, BBC1

"You know what? I just love the miracle days," said Monroe, stripping off the surgical gloves after successfully quelling the tremor of a patient with Parkinson's disease. "You're cruising for a bruising," I thought, a sentiment that ought to have been generated by context and character alone but which may also have had something to do with the fact that Monroe is played by James Nesbitt, among television's most infuriatingly perky performers. With those Ronald McDonald eyebrows arching high on his forehead, and the cocky rapidity of his delivery, he tends to exude self-regard in any part that isn't painstakingly written to forestall it. And Monroe isn't one of those parts.

Monroe is a "maverick" (they were actually shameless enough to put that term in the Radio Times billing), a neuro-surgeon who has a House-like ability to resolve medical problems his colleagues can't manage and a House-like ability to rub them up the wrong way. He revels just a little too much in his membership of the awkward squad. When he asks a colleague returning from pregnancy leave whether she's taken up Pilates yet, he's told to mind his own business and reacts with mock indignation: "What? Is a colleague's pelvic floor considered off-limits these days...political correctness gone mad." But Monroe's ability to deliver "miracle days" keeps him in employment.

Peter Bowker's script is an odd mixture of the enjoyably snappy and the sentimentally incredible. "A pint or domestic bliss?" Monroe asks a workmate as they clock off one night. "Neither. I'm going home," replies his jaundiced colleague. But later, when Monroe is advising a patient of the daunting odds he faces in surgery, the man replies as if he's a scriptwriter himself, self-consciously crafting a moment of poignancy: "You've got craftsman's hands," he says quietly. "My dad was a cabinet maker... you've got hands like his." Dim as this is as a way of deciding whether to undergo a possibly fatal medical procedure, he gets away with it. I thought Monroe might be rebuked by life (or Bowker) for his hubris about his healing powers. But no. Another miracle.

Now that it's reached its ninth series, the title of New Tricks is beginning to have a slightly uncomfortable edge to it. It still seems to be very popular with audiences and I guess with that cast it isn't entirely mystifying. But you still wonder how long they can keep it up. I haven't watched for a good while and was a little startled to find that it seems to be subsiding gently into Last of the Summer Wine buffoonery. Take the Snotty Receptionist in last night's episode, for example, who was straight out of a Stock Character cupboard and whose implausible, nose-tilted contempt actually undermined the joke she was part of. Or, far more embarrassing, take the notionally comic moment when Brian attempts to shampoo his dog Scampi, having become convinced that he might have a future in canine modelling. I wonder if you can you guess who ends up spluttering in the bath, covered with foam? I thought you might be able to. To see an actor of Alun Armstrong's calibre reduced to this kind of comedy floundering is actually quite painful.

I do wonder about people's appetite for plot too. You need some, of course, to give a narrative shape. But here there's a sense of scaffolding that exists to do nothing but hold itself upright for an hour, and to which has been bolted dialogue as familiar and interchangeable as Meccano components: "Why am I getting the feeling that you're lying to me, Mr Marshall", say, or "Look. You have to believe me! Alice was alive and well when I left her!" There were, to be fair, some attempts to get deeper emotional subtext into the whodunit, the only problem being that they sit very uneasily alongside the light-relief capering. Some new tricks are very definitely required.