‘The boundaries are stone wall mostly. But they’re rather old. I’ll have to get someone to check the wooded areas to see if there’s a collapse.’

‘That would be a good idea, sir.’

‘Come on up to the house anyway. The rest of the drive is OK.’

Cooper eased the Toyota over the last few yards of weed-covered gravel and parked next to a black Range Rover near the front entrance to the hall. Casey walked up behind them, sorting a ring of keys from his pocket.

‘I hope the house is more secure than the rest of the property, Mr Casey,’ said Fry when they’d introduced themselves. ‘Or are we likely to find sheep grazing in the reception rooms?’

‘No, no. I assure you, Sergeant, it’s perfectly secure.’

But Casey didn’t look entirely certain of that. And no wonder, if the property hadn’t been checked for a while. The decomposed sheep had been a bad omen. Cooper could imagine some of the scenarios now going through Casey’s mind. He’d be picturing himself opening the front door of the hall and confronting the unmistakable signs of large-scale theft or vandalism.

The front elevation of the hall itself wasn’t particularly impressive. It was built of limestone blocks, with sandstone corners and lintels in the local style. Its eighteenth-century mullions were its most attractive feature, but a jumble of awkward gables, mock battlements and nineteenth-century alterations had destroyed any symmetry it might once have had. Cooper could see why the dukes never thought of leaving the grandeur of Chatsworth for this.

There was a short flight of steps up to the door. Much of the mortar had disappeared from them, leaving gaps where dirt had collected and moss had darkened the stone. Casey seemed to hesitate before putting the key in the lock.

‘There’s a burglar alarm,’ he said. ‘The keypad is just inside the door.’

‘Presumably you know the code number?’ said Fry.

‘Of course.’

Cooper looked up at the yellow box tucked into an angle of wall formed by the addition of a Georgian wing.

‘Who would have set the alarm last?’ he asked.

‘Whoever had the task of checking inside the house,’ said Casey. ‘We’re supposed to inspect the property at least once a month, unless the weather has been particularly bad, in which event we’ll come down to see if there’s any structural damage.’

Casey looked a little embarrassed as he waited for Cooper to ask him when the last inspection had been, in view of the company’s staff shortages. In fact, Cooper didn’t need to say anything. As Casey put the key into the lock, he answered the unspoken question.

‘I’d have to look at the records back at the office,’ he said, ‘if you need details of previous visits.’

‘We’ll let you know, sir.’