ANYONE for an anniversary? Here's one. This month, it is exactly 21 years since Dennis Potter's The Singing Detective first went out on BBC One, burrowing across six Sunday nights toward Christmas like a hole clawed out by a fevered, infected rabbit from Wonderland.

A few years ago, some of the leading lights of our current generation of television writers - people such as Russell T Davies and Paul Abbott - could be heard bemoaning that critics had, to the point of cliché, made too much of Potter representing a golden age of TV fiction, his death in 1994 marking the symbolic demise of a certain kind of authorial voice. Their point wasn't to belittle Potter, but to make the case that a lot of fine, clever, lively TV drama is still being made in Britain.

But is it? We get fine one-offs in the social realist vein, but when it comes to the kind of resonant, audacious, adult and deeply personal mix of naturalism, fantasy, imagination, allusion and elusiveness Potter exemplified, what are we talking about? Life On Mars? Blackpool? Cape Wrath? The next series of Torchwood? Season 83 of Shameless?

The Singing Detective is on my mind because it's always the first thing I think of whenever I see Michael Gambon in anything - just before he briefly eradicates the memory of his brilliant performance in Potter's programme by being brilliant all over again - and because this week his brilliance is adrift in Joe's Palace (tonight, BBC One, 9pm), the new piece by Stephen Poliakoff, who, for better or worse, is the closest we have to an heir to the ornery Potter tradition.

Gambon plays Elliot Graham, a billionaire whose fame as the UK's eighth richest man is matched by his reputation as an eccentric recluse. He owns the stunning London mansion that is the palace of the title, but he doesn't live in it. No-one does. Instead, Elliot lives across the street. Still, he makes sure the empty old house is immaculately maintained.

Joe (Danny Lee Wynter) himself is the 17-year-old son of one of the cleaning women who tend to the house, who gets taken on as doorkeeper cum caretaker. Most of the time, he has the place to himself. He's not supposed to let anyone in, but makes an exception for Richard Reece (Rupert Penry-Jones), a young, married government MP, and his lover Charlotte (Kelly Reilly). Soon after, with the permission of Elliot, who is happy some kind of life is going on between the walls, Richard and Charlotte are using the house's empty bedrooms as a base for their affair.

He's an odd kid, Joe. Open but blank, observant but seemingly unaware of how other people are reacting to him and lacking any kind of social filter - if something pops into his mind, he just says it - he could have an Asperger's-like syndrome and, outside of a Poliakoff script, his chances of being employed to look after a London billionaire's property would be precisely zero.

But that's the thing with Poliakoff. His people are rarely meant to be people. Instead, they are ciphers, symbols, tools. In this case, Joe, who exists permanently on the surface of the present, is set in contrast to the troubled Elliot, caught and drowning down in the undertow of the past.

The reason he fears the house, which he inherited from his father, is that he is consumed by the idea that his father's fortune must have been founded on some deep, black secret. He has employed historians to trace the source of the wealth, but they have turned up nothing they find suspicious. Yet he cannot shake off the feeling that there is something horrible lurking there. And so his life is on hold, and so the house sits empty, something between a full-sized doll's house, a mausoleum and the haunted Overlook hotel of The Shining.

Joe's Palace is unmistakably Poliakoff, and, for that reason, brilliant and maddening in about equal measure. It moves at its own weird pace, with unashamed intelligence and a beautiful feeling of loneliness and history, and is littered with startling ideas and moments. Equally, it's often awash in irritatingly precious whimsy. Sometimes, the only thing grounding it is the astonishing veracity Gambon brings to his role; the man is a masterclass.

It should be noted that it is the first of two dramas. The companion piece, Capturing Mary, which focuses on parties that took place in the house during Elliot's father's time and boasts a brilliant performance by Maggie Smith, and a curiously disturbing one by David Walliams, follows next week. The two films can stand alone, but each echoes the other, and both show Poliakoff setting off along his own track, trusting that there is an audience willing to follow. That is exhilarating and exasperating at once: I'm glad there is still someone prepared and allowed to indulge himself to this extent; I just wish he wasn't the only one.