Dr Maryam Zamani holds a phial of blood up to her window overlooking Sloane Street. ‘It’s beautiful, isn’t it?’ she says. The blood has separated like a B52 cocktail after being ‘centrifuged’, but I suppose it’s beautiful yes, in this blessed SW1 light. It’s being used for a ‘medical-grade facial’, the details of which I am given in a medical-grade lecture by Dr Zamani, a surgeon, and the kind of person who assumes everyone understands words like ‘telangiectasia’ (that’s dilatation of the capillaries to you and me).