He was concentrating: he answered distractedly. ‘The valve removes air and creates a vacuum inside the flask.’

‘But the bird…’

He shrugged, smiled. ‘I can’t very well mount it in the cabinet if it is alive.’

I found myself watching in fascinated horror as the bird circled once or twice then wobbled drunkenly on its twig legs, failing to find purchase on the smooth glass. The doctor watched too, his face a mask of detachment. The bird tipped onto its side. Tiny feathers around its neck, shades of blue and black, trilled with the shudders of its body. All of the animal was just a heart now, that spun erratic with the strain. It rolled onto its back, one leg kicked and it was still.

The doctor unscrewed the lid. He wrote in a notebook as the bird lay on his other palm. Superb Fairy Wren, male. Sexually mature…

‘Good.’

He looked up, and must have registered the disgust in my expression. ‘Dear girl, the bird might be five years old. A falcon will kill it within a year. The bones will rot in the grasses on one of these godforsaken islands, and for what? You and I have just ensured this little creature will delight and inform for centuries to come. These are the pains and the pleasures of science, are they not?’

He removed his jacket, stretched himself into the space of the small room. I felt a deep languor, a desire to be done with the evening and recline. He must have sensed it for he took me firmly by the hands and led me to the bed.

‘Please,’ he said, ‘make yourself comfortable. It is the greatest honour I can imagine to have you in here.’ The words were soothing, as always. But smaller voices in me said that he had just killed a living creature to impress me. That my father would be sleeping outside the room, that he must know by now what had been going on.

There were so many competing forces at work inside me now. That tiredness that seeped all the way to my bones, the hot tea spreading warmth in the centre of me, an ache for his hands and his mouth that was new and frightening. And harder voices: responsibility, fear of being caught, a horror that any of this was happening at all.

In the shadows on the far side of the room the doctor was removing his clothes, item by item, unhurried. He was placing them on a chair, draping and folding with half a smile on his face. And now he walked to me; naked and tall, dusted silver, and the voices of complaint were turning to alarm and open mistrust, but other voices quashed them and I took him to me.