They swapped jerky thumbs up and hugged, entwining their fingers tight. Panicked speech bubbles erupted, spiralling above their heads. The ridge where they stood was eighteen metres. Before them was the deep. Who knew how far it went, but from the solid darkness Ray guessed it plunged down for hundreds of metres. She shivered, swaying with the current, holding Fari tight. She wanted to feel anger at Richie, up on the boat probably with a cold beer and a smoke; more irrationally at the stark depths before her. She even tried to conjure more upset, failing; she only felt joy that they were safe, that the current had pushed instead of pulled. She didn’t want to imagine what it might have felt like to be hauled down into the gloom.

Fari spasmed with the muscular thrust of an eel. His eyes were wide, fearful, and he exploded into action, kicking from the ridge. Fear pierced Ray again. This time she went with him, holding his fingers, looking in the direction he was staring, unable to see. Then she made out something: a vague, distant shadow. Drawing closer, growing larger, coming. So quick she couldn’t react.

At first Ray thought they were huge fish. Sharks, dolphins maybe. Swimming side by side, difficult to catch in misty light, but when they flipped their bodies, darting and swooping like kites, she realised the motion wasn’t right. They weren’t the correct shape. She couldn’t see details as the sun blocked their true forms, turning them into twin spectres, furiously writhing until they spun and dived, aiming directly for Fari. She shrieked, hearing herself, a fury of bubbles hiding the creatures from view. When the bubbles fluttered upwards, they stood upright before them.

She was breathing too fast, using excess air. Much as Ray tried to stop, she found it impossible. She tried to convince herself she’d seen incorrectly, or even that she was dive-drunk, yet every sense she possessed told her they were solid and real. These weren’t animals but some form of humanoid. Breathing without diving gear at eighteen metres, sculling like natural law. Beyond the beings, darting fish, oblivious to their presence. Beams of sunlight, thick and thin, rippled like curtains.

She felt Fari’s light touch, not wanting to look in case the creatures did something in response, mainly to him, although she needed his reassurance and risked it. They nodded at each other. OK? Yes. Bubbles exploded from his regulator as fast as hers, spinning, wriggling, escaping. Surface-bound. The people – for Ray decided that was undoubtedly what they were – floated a metre away, calm and motionless apart from curious expressions, the slight curve of smiles.