‘He led us to a cave down by the water, and we all climbed in there . . . You’ve gotta understand, we were excited. There’s nothing I loved more than exploring together with them like that, we did it all the time, going on walks or out on the boat. Alexandra was the nicest mum, and me and Forest . . . all we had was each other. But this time was different. Jesse . . . I could tell something was wrong, the way he kept looking through us rather than at us, but I didn’t know what. I just figured he was high.

‘Well, we were all down in that cave network. The three of us went into a cavern ahead of him, but instead of following us, he must’ve climbed up above and rolled down a boulder. All those rocks are loose . . . well, however he managed it, he blocked the entrance. Of course we scrambled back up, pushing at it, yelling for help – first from him, then from anyone. But . . . there was just silence. We were alone.’

Tears rolled down Huck’s cheeks.

Forest could barely breathe, but Huck had stopped talking.

‘And then?’ whispered Forest.

‘He’d planned ahead. When we climbed deeper into the cave, looking for another way out, we found Alexandra’s scuba gear. He’d left it there beforehand. That’s when she realised what was going to happen – he’d trapped us in a tidal cave. We were going to die. He’d put her gear in there so it’d look like she’d gone diving, or like she’d killed Forest and me in some kind of . . . murder–suicide.’

‘Why did he do it?’

Huck turned to him, frowning, as though it were obvious. ‘He didn’t want anyone else to find the Treasure Cave. That’s what Alexandra said, once the water started to rise.’

‘He was evil,’ said Forest. ‘Pure evil.’

‘Evil or not, he was gone. No one was coming to save us. Alexandra tried to put the scuba gear on Forest, but he refused. He . . . he put it on me instead . . .’ Huck wiped his eyes. ‘She used her diving slate to write a note, in case someone found us . . . after. We all knew we weren’t getting out of there. I suppose she didn’t want to die a meaningless death – she drew a rough map, leading to the Treasure Cave. Or maybe she just wanted revenge against her husband, her murderer . . .