He was about to answer when the door opened and a woman walked in. Perez thought Willow had been expecting her, that this was a pre-arranged meeting. The newcomer stood just inside the door, then approached them. She was wearing a bright-red coat, heavy brown boots and carried the smell of cigarettes with her.

‘I went to the police station this morning as soon as the ferry came in.’ Monica Leaze had the same nervous energy that Perez remembered from the launch of her exhibition. The same wiry hair and chestnut eyes. ‘They told me to talk to you here.’

‘So now we’re in a position to explain to Sandy about the ghost.’ Willow’s voice was light until she turned to the artist. Then she was fiercer than Perez had ever seen her. ‘If we’d understood earlier that you were involved, we might have prevented Hillier’s death.’

‘Of course I should have come before.’ Monica was playing with a napkin on the table, folding it into smaller and smaller squares. ‘But when I left Shetland I didn’t know Eleanor had died, only that she was missing, and that was always part of the plan.’ She turned to stare out of the window. A waitress brought coffee without her noticing. ‘It started out as a bit of a hoot, and a way to get Nell out of a financial mess. Nobody was really supposed to get hurt.’

‘Perhaps you could talk us through what happened.’ Perez thought he knew most of it, but Sandy was sitting on the other side of the table looking bewildered. The man had worked well on this investigation and his own version of the real Peerie Lizzie story was probably close to the truth. He deserved some answers to the make-believe one. ‘You met here in Shetland a couple of weeks ago. You and three others.’

‘Well, I’d known Eleanor for ages. We moved in the same arty circles, I suppose – my husband’s a director. I hadn’t come across Charles or Lowrie before. We came together that day; we were Nell’s team, her secret weapon. The four of us had lunch in the Hay’s Dock. It seemed like great fun at the time, a bit of a party, as if we were on some kind of secret mission.’ Monica paused. ‘That was the last time I saw Eleanor. Lowrie and Eleanor had flown in on separate planes, very cloak-and-dagger – Lowrie from Edinburgh and Eleanor from Glasgow, though they both started off in London. I was already here in Yell and Charles Hiller gave me a lift down to Lerwick.’

‘And what was the meeting about?’