He nodded again and she left the room.

They met Sinclair at the lighthouse at Hvidahus Point. Sandy was full of energy, like a dog that’s been locked up overnight and is ready for a run. Sinclair had seemed unbothered by the request to leave his office and talk them through the project. The fog wasn’t so thick here, but the day was still damp and grey and there was limited visibility, so the cliffs seemed to drop forever towards the sea, to disappear into the murk where the air met the water. There were few cliffs on North Uist, and Willow had always felt uncomfortable with height. She had the feeling that she might be sucked over the edge, or even that she might be pulled there by an irresistible temptation to jump. Just to experience the sensation of falling, of hurtling towards the water like a diving gannet.

Willow judged Sinclair to be in his sixties, but he walked without effort across the cropped grass. He was happy to tell them what he knew about the new energy project. He was a natural lecturer, concise and simple. ‘There are two forms of potential green energy to be harnessed from the water,’ he said. ‘With wave power, the mechanisms float on the surface and it’s the movement that generates the energy. Tidal power is quite different. For that there are turbines underneath the water. Imagine the wind turbines that we’re all used to – like the ones in the wind farm on the hill just outside Lerwick. The only difference is that these are powered by the tide instead of the wind.’ He paused, ignoring Sandy running after him, to check that Willow was taking in the information.

‘And what’s being planned for here?’ she asked.

‘Both eventually.’ He led them down a steep bank so that they were almost at water level. ‘This will be an experimental site, remember. But first we’re concentrating on the tide. There’s a tremendous race between here and the island of Samphrey. There are stories from local boys about the power of the water at this point. They say there’s only twenty minutes of slack tide at low water. When they were laying the pipes to Sullom Voe, Delta Marine did a rescue exercise – they threw a dummy into the sea to practise pulling in a man who’d fallen overboard. The dummy disappeared in seconds, sucked under by the currents, and was never seen again.’

‘What stage are you at?’ Willow still wasn’t sure how any of this was relevant.

‘We’re ready to set up a pilot project, using a local company to build most of the components and another to install the turbines. We need to strengthen the pier and rebuild the old hatchery close to it, widen the track a tad, but that won’t take long.’ Sinclair spoke with a breezy optimism.