She looked at him. “Sorry,” she said, and started walking back towards the jetty

She was OK, that’s what she kept telling herself. Unless the earth actually opened up and swallowed her right here on the beach, she was safe. It was buildings you had to watch for. That and tsunamis, but they’d never had one here yet in 25 years, and while this quake was sizeable it wasn’t the biggest she’d experienced.

The throb beneath her feet began to ebb away, echoing down into the mantle, the earth settling back.

The whole thing had lasted maybe 30 seconds. She wondered what number it was on the scale.

Then she thought of Tom. Alice and the girls. And herself. The mistress. The homewrecker.

The silence after the quake was ominous, forbidding.

If she called the police she would have to explain what she was doing here, what Tom was doing here. Then it would all come out.

His wife and family. Her mum, Brendan. Everyone would know.

She spotted something in the sand beyond his right hand. The old Nokia, the phone he used just for her. She looked around at the shore, wondered where his boat was.

The birds were returning, getting closer above her head. She picked up his phone and stared at it, wiped it on her dress to get the sand off.

She felt ridiculous in this dress now, a piece of fakery. She had been living a lie with Tom.

She looked at him.

“Sorry,” she said, and started walking back towards the jetty. Stinging

The spray from the prow dampened her dress and felt like a slap in the face.

She closed her eyes and gave herself over to the salty tang of the sea stinging her skin.

The outboard motor was at full throttle, the whine of the engine filling her ears as the boat bucked over the waves.

She headed east towards the widening mouth of the firth, refusing to look at the island behind or the coastline to either side.

If she kept going all the way to Scandinavia she would never have to deal with any of it.

The motor strained and she became aware of the clamour of it out here on the empty water. She cut the engine and the silence pressed down on her, the slap of wave on hull the only sound.

She sat for a long time listening to that noise, trying to find a pattern in it, but it was disjointed and random.

Eventually she turned back to the Inch.

It looked like a cancerous growth on the skin of the water, the two volcanic lumps of the vents rippling down to the stark southeastern cliffs.

The northern beach and jetty were invisible from here. The same for the cove where Tom lay.

She looked south to Joppa and Portobello. The sun had set but the sky was still eerily bright, that unsettling paradox of Scottish summertime.

In this light, the beach seemed smeared across the land, thick painted brush strokes in front of the precise sketch lines of the houses behind.

She tried to pick out her own place from the row of low tenements at the eastern end of the shoreline.

Some lights coming on in the front rooms, but she couldn’t see which was hers.

She wondered if Halima was in the kitchen knocking together something spicy with a large glass of Rioja in her hand.

Or Iona, throwing clothes around trying to decide what to wear for tonight’s shift.

People she loved going about their lives.

She stared at the stumpy, flat-roofed houses and wished she was inside, sharing department gossip with Halima or shouting at Iona to pick up after herself. Reduced

She looked at the bigger Victorian properties along the prom.

She could pick out St Columba’s easily with the observation tower poking up from the sprawl of dark stone.

Her mum would be there. She was diminishing every day, retreating from the world one breath at a time.

So much life reduced to a bag of bones, half her stomach cut away, growths in her pelvis and liver, tangled up her spine.

Only a matter of time.

Surtsey thought about Tom. She pictured his slender fingers on her hips that first time, a reassuring touch to her elbow in the office, his goofy smile whenever she walked into the room.

She’d been pushing them away but now the thoughts slipped in.

How had it happened? Maybe he fell and hit his head. But where was his boat? It could be moored beyond the cove, but why do that?

If his boat wasn’t there, that meant someone else had taken it or it had drifted away.

If someone else took it, how had they got to the island themselves, where was their boat?

Did they come with Tom, was it someone he knew? Was it murder?

Maybe he fell and hit his head on a rock, staggered forward onto the beach.

The hardened tephra and palagonite tuff were razor sharp in places, an edge to the wrong part of your head and you’d be in trouble.

She hadn’t examined his wound closely, hadn’t looked around for rocks or boulders, too keen to escape.

It must be lonely back there on the island. When eventually it got dark in the early hours and the wind picked up along the Forth, he would need a blanket to keep warm. Stupid thoughts, chewing her up.

She trailed a hand in the water, cold against her fingers, and shivered as a breeze stirred around her.

Too quiet, too much time to think. She needed to be moving, active.

She started the engine and pointed the boat towards shore, opened the throttle and picked up speed, flecks of spray in her face.

She opened her mouth and tasted the salt. Burned

She was at the east end of Portobello beach in 10 minutes. She angled the prow alongside the last groyne and drove the boat as close as she could, then cut the engine, flipped off her shoes and jumped out, pulling the boat in on the towrope.

She heaved it onto the trailer she’d left sitting in the wash and fastened it, then hauled the whole thing up the sand to the gap in the low seawall, then onto the prom.

Her muscles burned as she pulled the boat and trailer round the back of Esplanade Terrace onto the cobbles of Joppa Park.

She stopped at the back of her house and opened the boatshed doors, wheeled the trailer inside.

She was panting as she dropped the trailer handle, hands on her knees, bent over to get her breath back. Eventually she stood up.

From the small, cobwebbed window of the shed she could see into the kitchen at the back of the house.

Halima was there, drinking and cooking, just as she had pictured.

More tomorrow.