The waves were coming over the top of the sea wall by the time the three had made their way to the bench. Lily was soaked through, despite her raincoat. The wind threatened to pick them up and toss them over the wall and they bent double as they walked, driving themselves into the storm. They held hands, salty, slippery fingers anchoring them to each other.
“This is crazy!” yelled Jay.
The wind whipped his words away, the bellowing thunder drowning him out. Neither of the girls heard him. A flash of lightning forked across the sky. Lily counted one, two – boom! The storm was right on top of them. A wave came flying over the wall, engulfing them all for a second. Lily screamed, immediately regretting it as her mouth filled with seawater. She spluttered, spitting it out and scrubbing at her tongue with the back of her hand.
The lighthouse was at the far end of the promenade, on the tip of a craggy outcrop of rocks. Coated with seaweed and slippery at the best of times, the path that stretched before them now was almost impassable. They made their way in tiny sideways steps, like a parade of crabs. Every so often they’d have to stop and turn their backs to the sea, bracing themselves against a particularly vicious barrage of waves. Lily had never been so thoroughly drenched in her whole life.
The lighthouse, which seemed postcard-tiny and adorable from the beach, was enormous up close. It towered above them, its surface furred with soaking moss, creaking ominously with every furious gust of wind. Lily put her hand up to her eyes and craned her neck back, peering up towards the darkened lamp of the lighthouse.
“It’s the perfect place to hide something,” she yelled over the storm.
“I know,” yelled Sam. “Hiding in plain sight.”
They felt their way round the bottom of the lighthouse until they came to what must have once been a door. It was encrusted with barnacles and rust, coated in the same slimy film as the rest of the building. Lily ran her palm over the surface, her fingers eventually picking out the shape of an enormous metal ring. She pulled it out with a sickening sucking sound, turned it and yanked. The door stayed firmly closed. She tugged again and again. No joy. It was completely stuck. Sam and Jay reached around her, closing their fingers round the ring. Sam grimaced.
“Eugh! That’s so slimy.”
Lily wrinkled her nose in agreement, before bracing one foot against the wall.
“On the count of three? One, two, three!”
They pulled as one, throwing their full combined body weight behind it. With an agonising screech, the door opened just a little. Just a little was enough. They wriggled through the narrow gap into the lighthouse.
The sound of the storm was muffled inside, the howling wind sounding mournful and far away.
“We’re probably the first people to step inside here in about a hundred years,” whispered Sam.
Lily pulled her torch from the pocket of her waterproof and pointed it at the spiral steps in front of them. They had probably been a deathtrap when they were brand new and the years since had not been kind to them. They were narrow and twisting, some of them rusted all the way through. Lily put her hand on the railing and pulled. It swayed under her fingers. This did not fill her with confidence. She turned back to her friends.
“Slowly,” they agreed.
Lily went first, gripping the railing. Even a faulty railing was better than nothing on such steep steps. She prodded at each step tentatively with her toe before putting her weight on it, skipping a few steps that shuddered under her. Looking up made her feel dizzy, so she focused on each step in front of her, trying not to think about the storm raging around them, making the old structure groan under its onslaught.
“These circles are starting to make me feel sick,” said Sam.
“Agreed,” said Lily. “How did anyone do this?”
She completed another tight circle and stopped dead, making Sam crash into the back of her with a little cry.
“What is it? Why have you stopped?”
Lily leaned out of the way, to show Sam and Jay what was in front of her. It was a door. She shoved it open, stepping tentatively through.
“Oh, wow,” she said, unable to hide the glee in her voice.
“Is it a diamond?” said Sam, scrambling through after her.
“Not that good. But look.”
They were in the lighthouse keeper’s living quarters. The wooden boards of the floor must have been polished once but were now dull with age and salt. The patterned rug was moth-eaten and worn. An armchair stood in the corner, its upholstery spilling out and the remains of what looked like a seagull’s nest instead of a seat. There was a tiny stove, a cast-iron kettle, a pile of long-forgotten books.
“This is the coolest thing I’ve ever seen,” said Lily.
Rain pelted the window on the far side of the room. Lily wiped the dirt from its surface and peered out. Nothing but black.
“This must be beautiful when it’s light.”
“And when we’re not in the middle of an enormous storm,” said Jay.
As if to emphasise his point, the building gave an emphatic shudder.
“OK,” said Lily. “We’re assuming something is hidden here. Either another clue or…”
She could hardly bring herself to believe it, never mind say it aloud.
“Or a diamond the size of a man’s fist,” said Sam wryly.
“Right. So we have to look around.”
They pulled open drawers, and looked inside the stove and the cast-iron kettle. They pulled back the rug and thumbed the soggy books. They looked behind the picture frames on the wall for secret safes. Despite its abandoned condition, Lily couldn’t shake the feeling that they were rifling through someone’s belongings – that at any second the lighthouse keeper could burst in and demand to know just what they thought they were doing. The room was small and it didn’t take them long to search. They found nothing.
“I guess we keep going,” said Jay.
“I guess we do.”
Lily crossed to the far side of the room and opened the door. She immediately regretted complaining about the spiral stairs. In front of her, leading upwards, was a long wooden ladder. She looked behind her and saw her own pained expression reflected on the faces of her friends. She placed a hand gently on the rung in front of her. The wood was damp and swollen. A splinter lodged itself in her hand as she gripped. She stepped apprehensively on to the bottom rung. It groaned underneath her but held. She stuck her torch between her teeth and jerked her head at her friends. The three started to climb.
The sound of the storm grew again as they climbed and Lily was aware that it was getting colder. Her torch illuminated a wooden trapdoor in the ceiling, warped and bent in its frame. She braced her shoulder against it and shoved, disgorging a shower of lichen and wood shavings into the upturned faces of her friends. They spluttered beneath her.
“Sorry,” she said round the handle of her torch.
The trapdoor creaked open and fell away with a slam. Lily pulled herself up through the gap, then reached down to help Sam and Jay. She wiped the handle of her torch and swung it around. They were in the beacon room of the lighthouse. Darkness was the only thing visible through the filthy windows on one side; on the other, the lights of the town glimmered in the distance. Lily felt as though they had climbed forever, but the movement in the blackness outside worryingly suggested that the waves were now coming this high, battering against the glass.
In the centre of the room was the old lighthouse beacon. Nestled inside, where there should have been a lamp, was a diamond.