‘Daylight helps,’ Tilly agreed. ‘It’s a shame Luke can’t be here. What will you do if it turns out that he has discovered a new species? Will you publish a paper?’

‘Oh, yes, once the research is done. Probably in Nature magazine. Don’t worry, your friend will get the credit of discovery. But,’ he added, pushing at his spectacles, ‘we’re getting ahead of ourselves. Let’s wait until we see what we’ve got.’

At the cave, Tilly pulled up and sat a moment before alighting. She felt the greatest disinclination to continue, but Des, parking behind her, walked briskly towards the entrance, waiting with obvious impatience for her lagging steps to catch up. He carried a large torch, prompting her to caution him about the presence of the bats.

‘Don’t shine it up.’

‘Not until I say, anyway,’ Leary said singlemindedly. He looked every inch the mad professor, his beanpole length echoed by the now fully extended net handle and the box tucked under one arm. He kept pushing at his spectacles, his eyes gleaming with anticipation.

‘You’ll not be entering yet, sir,’ Des said firmly. ‘You’ll stay with the constable until we’ve located the weapon. Is that clear?’

Leary grudgingly agreed and, resisting the urge to clutch at Des’s arm, Tilly followed him into the cave. It was as humid and smelly as she remembered. It was only her imagination, she told herself, that she fancied she could still catch the taint of death in the muggy air. The darkness was disorienting, and she stared about in bewilderment trying to picture where she had been when she threw the gun into the fissure. Des’s prompting didn’t help and in the end she said, ‘Just give me the torch. I can’t see anything while you wave it about.’

There was still the shape of one cage imprinted in the guano, the rest destroyed by foot traffic. She stared at it, picturing the stacked shapes next to which Luke had sprawled. She had hit Matt and run that way to secure the gun and distance herself from the horror of Gerry’s corpse, so it must be somewhere here, she thought, moving along the cave wall, that she had spotted the break in the rock.

The rustle of wings sounded above her and the fine disturbed dust caught in her throat. Sweat beaded her forehead and her heart pounded with remembered fear. She would never willingly enter a cave again. Then the light lit on a deeper blackness within the glistening stone and she breathed out thankfully. ‘Here. I dropped it down there. And I really don’t think you’ll get it out again.’