‘What do you wear for these otter trips?’

‘Camouflage jacket and trousers and a woolly hat.’

‘In the summer?’

‘Yes. I don’t get hot. I have a small tent that I use as a hide. Do you want to see pictures of egrets?’

‘No, thanks. Did you see anyone else?’

He thought hard. ‘There was a man on a bike. He had a head-torch, which annoyed me because it might have disturbed the otters. But he rode onto the island and I didn’t see him again before I left.’ Tilling started playing with the camera. ‘I’ve got some water voles if you want?’

Wickens, trying to avoid being drawn into Tilling’s hobby, asked to use the toilet. He was directed upstairs, first on the left. He negotiated more threadbare and grubby carpet, and squeezed past an old stairlift, clearly not in use going by the fractured seat. A smell, worse than stale, assailed his nostrils. On the landing he noticed a tea trolley on which several dirty plates were stacked. Wickens stepped back from the stench, and banged into the trolley, setting off metallic clinks. He opened the bathroom, took one look and thought better of it. Turning to come downstairs, he ran into Tilling, who was coming up the stairs.

‘You didn’t wake Mum up, did you?’

‘Wasn’t she awake already?’

‘She has sleep apnoea, among other things. She’s not well. She’s been bedridden for years, and now she’s got problems with her spine. It’s gradually crumbling, and she’s in pain.’

Tilling escorted Wickens back to the front door. The PC escaped gladly to his car, breathing in some fresh air. It was only when he was safely inside and had already started the engine that he looked up at the gable. That would be the room Tilling’s mother was in. The curtain was drawn but between it and the glass, moisture could be seen running down the inside. Poor Mrs Tilling, being looked after by a man like Gary. Not the most natural carer.

Unless you were an otter, perhaps.

After the policeman had gone, she called loudly again from upstairs. He never had any trouble hearing her.

‘Did you discover why they came here?’

‘I think he was interested in otters. But not egrets.’

‘I don’t think so, Gary.’

‘It was the car registration. Got caught on a camera.’

‘You’ve got to be careful,’ she said.

‘Yes Mum.’

‘You’re a good boy, Gary. You’re a great comfort. And there aren’t many of them left for me in this world.’

‘No Mum.’

‘Can you fetch me some of the new painkillers? It’s bad again.’

‘Yes, Mum.’