‘I will,’ said William, producing the bottle Dr Lockhart had given him, which at least produced a flicker of concern on Hamish’s face. ‘Meanwhile, I would ask you to remain in your cabin while I continue with my enquiries.’

‘And if I don’t, Chief Inspector, what will you do? Have me clapped in irons before walking the plank? I don’t think so. Why don’t you run along.’ He raised his glass in a mock toast.

William left, convinced that, like the doctor, Hamish Buchanan had something to hide. But both of them in their own way had made him aware of just how little time he had to find out what that something was. ‘During the first forty-eight hours of a murder inquiry, you only go to sleep if you fall asleep’ was one of The Hawk’s favourite mantras. And then only after you’ve made an arrest.

William quickly made his way back to deck three, where he was pleased to find Franco posted centurion-like outside the entrance to the dining room.

‘Any ideas yet about who the guilty party is?’ whispered Franco as he opened the door.

‘It may just have been a heart attack,’ said William, without conviction.

‘Fraser Buchanan had the constitution of an ox. He’s never had a heart attack in the past that I’m aware of, despite what the doctor claimed. So whatever was in that flask killed him.’

William suspected Franco might be right, but intuition wasn’t proof. When he entered the dining room he found James, head down, writing furiously. William sat next to him and studied the seating plan he’d drawn. He then turned over several other menus one by one and began to read the conversations from earlier in the evening that James had meticulously chronicled. Words had been crossed out, replaced, but the tenor of the conversation was clear for him to see.

He’d reached the back of the third menu when he stopped and reread a paragraph, not twice, but three times.

‘Are you sure about this?’ he asked, pointing to half a dozen lines James had underlined.

‘Certain,’ said James, not looking up. ‘I have no evidence of course, so I can’t prove it. But I’m sure I know where you’ll find the other flask.’

‘I’ve already seen it,’ said William.

• • •

They lay back exhausted. It was some time before she spoke.

‘I suppose this can’t go on for much longer,’ Jackie said as she pulled the sheet up to her chin.

‘We won’t have a lot of choice,’ said Ross, as he lit a cigarette. ‘If we don’t end it now, I have a feeling The Hawk will.’

‘I’ll miss you,’ she said quietly.

‘We’ll still be seeing each other every day.’

‘It won’t be the same,’ she said, nestling up against his shoulder. ‘Do you think The Hawk knows about us?’

Ross inhaled deeply before he replied. ‘Of course he does. Nothing gets past that man. Out of interest, how do you get on with the choirboy?’