The path veered left, before cresting a small rise. From the top, they saw an astonishing sight. A small section of landfill had sunk into a kind of depression; perhaps it had collapsed partway down an old mine-shaft before blocking it, leaving what looked like the interior of an inverted cone, though it wasn’t steep. At the bottom, some thirty yards down, it flattened out a little, but centred around a pit, where twists of splintered furniture, broken planks and piles of mouldering newspapers had sagged into the earth. On the far side stood the figure of Sister Cassie, hands clasped in prayer, and on the near side a small group of about eight of her bent, tattered followers either standing or seated on broken chairs. There was a terrible reek in the air, while plague-like clouds of flies swirled around them.

The ex-nun interrupted her service, eyeing the cops sternly as they descended.

‘And why are you here, detectives?’ she called out. ‘We are doing nothing illegal.’

Lucy stumbled downhill towards her. ‘What exactly are you doing, Sister?’

The ex-nun still looked vexed. ‘Performing a holy ritual, of course. Burying these poor, harmless creatures that were so viciously treated.’

Lucy already had half an idea that she hadn’t interrupted a human funeral, but on reaching the bottom of the depression, she scrambled over anyway to look. The stench of decay thickened, becoming almost intolerable. Flies swarmed aggressively. In truth, it was a nightmarish scene, almost demonic: the figure of the nun, cadaverous, degraded, draped in her dirty, ragged raiment, yet hands joined in prayer as she stood upright on a hillside of waste and filth, a storm of winged horrors buzzing around her.

The contents of the pit were the crowning, hellish glory.

Lucy gazed down on a tangle of butchered, half-burned, half-rotted forms crammed on top of each other. Maybe ten or eleven, maybe more. But trampled down hard, with brute force, until they’d almost coagulated into a single mass. Even then, occasional body parts were visible: a canine snout, complete with whiskers and nose; a tongue lolling over exposed fangs; a twisted, shrivelled paw.

‘Good Christ.’ Peabody gagged.

In only two and a half years he’d already attended more death scenes than anyone in normal life could imagine. But still this was almost too much for him. He’d gone green in the cheeks; one heavy-knuckled hand clamped across his nose and mouth.

‘The poor dears,’ Sister Cassie said, hands still joined, smiling benignly down. ‘Several days ago, one of my regulars came across them during his wanderings. He too was horror-stricken.’