Tilly was touched. ‘Why, Luke, that’s quite poetic. But yes, you’re right. I think the expense of the trip was worth it, just for that one day.’

‘And her cooking.’

‘Of course,’ she agreed dryly. ‘By the way, do you know what Jane’s like in the kitchen?’

‘No, well, she shares accommodation. Student meals, I guess – noodles and take-aways, cup-of-soup, chips – that’s what I lived on at uni. When we’re married maybe you could give her some tips?’

Tilly grinned derisively. ‘Huh! Hasn’t helped you much. By the way,’ she said, for they were now passing by the overhang where the paintings were, ‘what’s the go with the artwork? I forgot to ask before.’

‘Graeme’s organising that. The old fence will go – it’ll be railed off and have a boardwalk for protection, and he’s going to see if there’s an elder from the area he can contact. Maybe there’d be somebody willing to guide the tourists, tell ’em the stories behind the paintings.’

‘Looks like next year will be an interesting one, especially if your bats turn out to be a real find. Maybe you could specialise, Luke? Become a well-known chiro-whatever – bat fancier. Write books, be on TV talkshows, earn big bucks.’

‘I like the job I’ve got,’ he said mildly. ‘Professor Leary might get himself interviewed, but I can’t see that— Hang about!’ He was slowing for the series of gutters just before the cave, and now Tilly saw it too, the back end of a closed, long-wheelbased Land Rover pulled off to one side in the scrub. ‘Who’s that? They must be in the cave. What the hell is going on here?’ Luke stamped on the brakes, switched off and sprang wrathfully from the vehicle even as Tilly was stuck wrestling with her seatbelt that had jammed shut.

A dreadful premonition gripped her as she tore herself free and thrust the door wide. ‘Luke, wait! Don’t go in there!’ But he was already on his way. His lean form vanished from sight, then she heard a shout, too muffled to tell if it was Luke’s or someone else’s, and then nothing. The seconds crawled stickily by, filled only with the buzz of flies as she hovered indecisively by the vehicle, but in the end she couldn’t not know. Her heart in her mouth, she pulled the seat forward, searching feverishly for anything that could be used as a weapon, and settled for the unwieldy jack-handle, which she grabbed from its metal clasp.