"Oh go one ... you're a girl!"

TV In case you missed the trailer which has played about a hundred times over the past month, Casanova began tonight on BBC Three in a graveyard preview slot, rather like a weekend film preview in the hopes of creating good word of mouth before it turns up on a main channel. It's an interesting strategy, especially with something which is obviously a premium series for the beeb, and it should really pay off.

Because it's absolutely tremendous. From the opening shot which offers the ageing Casanova played by -- my god -- Peter O'Toole putting words into the mouth of his younger self essayed by instant star David Tennant as he tries to talk himself out of what is obviously yet another scrape, the show just rattles along throwing out costume drama convention after convention. It's been tried before in everything from the film Plunkett and McLean to a Channel 4 version of Anna Karenina from a few years ago, but here it actually works.

It more or less demonstrates why Russell T Davies is one of the best five script writers on tv. In the dialogue he manages to offer a contemporary blende without it jarring with the period. Using the framing device over the older telling the story of the younger, he manages to cover a lot of ground in plot and character terms but without the audience feeling short changed that they're missing the really good bits. But he also knows when to pull back and let the pictures tell the story. There is a great moment in which two people communicate across a crowded room, something I've never seen before in frocks and coats and it's utterly real.

But the directing and editing are fluid as well. Sheree Folkson previously worked on contemporary dramas like Burn It and the The Young Person's Guide to Becoming a Rock Star both of which had a kinetic energy which re-appears here. Forget establishing shots -- don't need them -- they'll just get in the way of the sight gags. The closest comparison I can think of is early Simpsons, that use of mounting montage leading to a punchline, comedic or emotional. I once went to a workshop with some people from Red Productions who are one of the companies behind this and they emphasised a philosophy of telling the story through what you can see and this really embrases that philosophy. The photograph is sumptuous as well; I'm not a huge fan of the Digital Video the BBC are using on their shows nowadays (tends to seem a bit washed out) but there are moments here which have the feel of a pure technicolour production.

There's all that and there's the cast. I said earlier that David Tennant is an instant star, and he really is. He's just channeling the always excellent O'Toole's charisma to create this uberpersonality -- that ability to be totally likeable even when he's (possibly) doing some bad things. Even with all the above the show would flatten out if he wasn't so good. To drop the inevitable reference, he has the magnetism of a young Tom Baker in his series of Doctor Who (although he sort also reminded me of Paul McGann in the audios -- that kind of curious happiness).

I'm also inevitably going to say that Laura Fraser is luminous, but she just is. I was afraid she'd just be getting a cameo, but she's Casanova's life long dream, always on his mind. The camera looks longingly at her in way I've not seen since Small Faces and underlines what a tragedy it is that she's not a STAR! Hopefully this will change that when it turns up on the main channel. I've not seen Rose Byrne before, but it takes something to match O'Toole yet there she is battling away as Edith the maid. I don't want to talk about the rest of the cast because it would give too much away but all are great too.

Just an excellent, excellent thing. If you missed it, I'd wait for the repeat before diving in. I'd imagine that you'll be losing a lot of the emotional resonance if you're just turning up for part two next week...