‘I must say I’m impressed,’ he said. ‘I’ve never been here before.’

‘Lost in a marsh punt in a sea mist it can be terrifying,’ she said. ‘In some places there are quicksands and mud-holes deep enough to swallow a cart.’

The closer they got to the estuary, the more the mist closed in on them until visibility was reduced to no more than twenty yards. Finally the track emerged into a wide clearing of rough grass surrounded by thorn trees. Craig’s Jaguar was parked under one of them and Miller braked to a halt.

‘We have to walk from here,’ Harriet said. ‘It isn’t very far.’

They followed a narrow path through the reeds. Wildfowl lifted out of the mist in alarm and somewhere a curlew called eerily. The marsh was stirring now, water swirling through it with an angry sucking noise, gurgling in crab holes, baring shining expanses of black mud.

‘If we don’t hurry we might miss him,’ Harriet said. ‘The tide’s on the ebb. The best time for duck.’

She half-ran along the track and Miller followed her and suddenly, the wind was cold on his face and she called through the rain, waving her hand.

The mist had cleared a little so that one could see the river, the houseboat moored to the bank forty or fifty yards away. Duncan Craig was about to step into a flat-bottomed marsh punt and straightened, looking towards them.

He was wearing an old paratrooper’s beret and combat jacket and carried a shotgun under one arm. He stood there staring at them, one hand shielding his eyes from the rain and then ran forward suddenly.

His face was white and set when he grabbed Harriet by the arm, the first time Miller had known him to show real emotion. ‘What the hell are you doing here?’

Harriet was bewildered by the anger in his voice. ‘What is it, Daddy? What’s wrong?’

‘We tried to arrest Max Vernon early this morning, but he gave us the slip,’ Miller told him. ‘I thought you ought to know he was on the loose.’

Craig gave Harriet a quick push forward. ‘Get her out of here, Miller! Get her out now before it’s too late!’

Harriet swung round, her face white, and Miller said softly, ‘My God, you’re actually expecting him, aren’t you? You’ve arranged the whole damned thing?’

‘Every step of the way.’ Craig patted the shotgun. ‘Vernon shall have his chance – all part of the game.’

‘It isn’t a game any longer, you bloody fool,’ Miller said. ‘Can’t you get that through your head? If Max Vernon comes looking for you he’ll have only one thought on his mind.’

‘Which suits me just fine.’ Suddenly there was iron in his voice. ‘No more arguments. Just get Harriet out of here.’