The man had seemed strangely familiar with the castle and its concerns, and it briefly crossed her mind that he might be Lord Larne himself, but she dismissed the thought. That ill-tempered curmudgeon had never written the letter that had charmed her. Probably a family retainer.

She could see where she was going now, the shore lights, and far beyond them the lights of some huge building that must surely be Larne Castle. Straight ahead for the bridge. She squinted, trying to detect the start of the railings. With her attention thus occupied she didn’t realise how far she’d driven until she found herself surrounded by water.

‘I’m in the sea,’ she said, aghast. ‘Where’s the bridge?’

But there was no bridge, only a causeway, fast vanishing under the incoming tide. With horror she saw that the shore was fifty yards behind her. The waves were swelling strongly, and a sickening lurch warned her that her little car wasn’t built for this.

She couldn’t go back. It would have meant trying to turn the vehicle and she didn’t know if the causeway was wide enough. Besides, retreat wasn’t in her nature. She must get ahead as fast as possible. The water had covered the road by only a few inches, and she could just about discern it.

But it grew harder and harder to hold her course. She slammed her foot down, trying to force her way through, but the next moment a huge wave lifted her off the ground, sweeping her sideways, and suddenly she was right off the causeway and sinking.

She tore at her seat belt and just managed to get it open as the car went down. Then she was free, dog paddling like crazy, with no idea where she was.

‘Here! Over here!’

The voice came from behind her, and she struggled around to see the man who’d stopped her back on the road. He was waving the torch to attract her attention.

‘It’s not too deep,’ he yelled. ‘You should be able to touch down, a beanpole like you.’