‘Great. Hold on.’ The Fast Ice and screw racks were still attached to Eddie’s harness; he fumbled a foot-long rod into the chuck, then drilled it into the wall. Once it was in place, he gripped it with one hand and reached down as far as possible to take hold of Cheng’s rope. ‘Okay, I’m going to pull you up. Ready?’

Cheng nodded. Eddie braced himself, then hauled. Even with eight inches of steel embedded in the cliff, he still heard the ice around the screw moan, but it held. The youth rose higher, clawing at the ledge before finally bringing one elbow over it. ‘Now lift your foot!’ The Yorkshireman took Cheng’s whole weight for a moment as he raised his leg and kicked his crampon spikes into the wall. ‘That’s it, keep going!’

Cheng brought himself high enough to hook his foot over the ledge. Eddie helped him fully onto it, then climbed up beside him. Crouching, he reattached the crampon to Cheng’s footwear. ‘For fuck’s sake, son!’ he snapped. ‘It helps if you actually fit them to your fucking boots properly!’ There was almost a centimetre of play around the toepiece. ‘I thought you said you knew what you were doing?’

‘I . . . I thought it was secure,’ Cheng replied, unable to meet his eyes. ‘I’m sorry, Mr Chase. I should have let Mr Naider check them . . . I just didn’t want to seem useless.’

‘There’s useless, then there’s worse than useless,’ Eddie growled as he tightened the crampon. ‘That’s when you get other people hurt as well as yourself. At least if you’re just useless, I can look after you.’ He straightened, using the drill to attach a replacement screw and carabiner and clipping the line through it. ‘All right. Wait for me to get across, then start after me. And don’t fuck things up again.’

He made the crossing, shaking his head.

Nina awaited him. ‘Kinda harsh, weren’t you?’

‘I should’ve been harsher. The kid could’ve killed himself.’

She shared her husband’s view, but at the same time felt sympathy for Cheng. ‘He’s just young – and he’s obviously a nerd. He probably felt threatened by you.’

‘Well, he definitely does now.’ Eddie stood with folded arms and watched as Cheng resumed his journey, considerably more carefully than before.

Eventually he reached the ledge. ‘Are you okay?’ Nina asked him.

It took him a moment to find his breath. ‘Yes, thank you, Professor Wilde,’ he said, still avoiding Eddie’s hard gaze. ‘I . . . I should have been more careful. I’m sorry.’

‘You made it in one piece, that’s the main thing. Let’s try not to break rule number one again, huh?’

Imka resumed her crossing. Eddie watched her progress, but Nina turned her attention back to the strange object above them. Cheng stood beside her. ‘It’s so big,’ he said, awed. ‘I never thought . . .’