You look a little lost, my dear,' a nun says behind me, and I jump. 'Were you...

You look a little lost, my dear,' a nun says behind me, and I jump. 'Were you interested in seeing the Bevington Triptych?'
'Oh,' I say. 'Erm... yes. Absolutely.'
'Up there,' she points, and I walk tentatively towards the front of the chapel, hoping it will become obvious what the Bevington Triptych is. A statue, maybe? Or a.. a piece of tapestry?
But as I reach the elderly lady, I see that she's staring up at a whole wall of stained glass windows. I have to admit, they're pretty amazing. I mean look at that huge blue one in the middle. It's fantastic!
'The Bevington Triptych,' says the elderly woman. 'It simply has no parallel, does it?'
'Wow,' I breathe reverentially, staring up with her. 'It's beautiful.'
It really is stunning. God, it just shows, there's no mistaking a real work of art, is there? When you come across real genius, it just leaps out at you. And I'm not even an expert.
'Wonderful colours,' I murmur.
'The detail,' says the woman, clasping her hands, 'is absolutely incomparable.'
'Incomparable,' I echo.
I'm just about to point out the rainbow, which I think is a really nice touch - when I suddenly notice that the elderly woman and I aren't looking at the same thing.
She's looking at some painted wooden thing which I hadn't even noticed.
As inconspicuously as possible, I shift my gaze - and feel a pang of disappointment. Is this the Bevington triptych? But it isn't even pretty!
'Whereas this Victorian rubbish,' the woman suddenly adds savagely, 'is absolutely criminal! That rainbow! Doesn't it make you feel sick?' She gestures to my big blue window, and I gulp.
'I know,' I say. 'It's shocking, isn't it? Absolutely...
You know - I think I'll just go for a little wander...