"What has nature ever done for us?"

Tony Juniper spoke on the above theme today, Day 3 of the Cheltenham Science Festival. He sought to highlight the choice we face between protecting natural systems and growing the economy in conventional terms. George Osborne, for instance, talks about "green tape" (environmental regulation) as a drag. No value is placed upon nature, and yet our economy is dependent on its much-threatened diversity. Bio-mimicry, pollination, water all came under scrutiny, but he would perhaps sum it up like Arthur Fallowfield: "I think the answer lies in the soil." An excellent talk, if a little short on jokes.

These were however in regular - if infrequent - supply in the National Theatre's "Frankenstein". I missed the live relays earlier in the year: to tell the truth, science fiction isn't my usual cup of tea, but having heard praise for both production (Danny Boyle) and acting from so many quarters, I plucked up courage to go along to the repeat this evening (with Benedict Cumberbatch as the Creature).

First and foremost this is a triumph of production - both in the theatre itself and in relaying it to a cinema audience. Since Phèdre almost three years ago, the RNT's technique has improved dramatically, in both senses of that word.

Then there's the cast, led by the amazing Cumberbatch and Jonny Lee Miller, but with excellent support from amongst others Naomie Harris (one to watch).

And finally, underlying it all, the imagination of Mary Shelley: truly, a remarkable achievement on her part to prophesy so acutely on the theme of Tony Juniper's lecture: we interfere with nature at our peril.

The photograph shows the entrance to The Screening Rooms, Cineworld's recently-hatched boutique sibling - to go there is certainly a luxury experience when compared to ascending the escalator to the popcorn-infested multiplex next door.