Even under normal circumstances, the sudden sight of this spectre in such close proximity might have made Lucy jump. It did more than that now: a yelp caught in her throat and she stumbled backward, bracing herself against the cashpoint ledge with her hand.

And yet the figure came straight on towards her, the cape so long that it was almost gliding.

Though momentarily transfixed, Lucy caught movement in the corner of her vision. She assumed it would either be Tucker or Smiley emerging from the alley on the far side of the Green, having seen what was happening before she had. But she couldn’t take her eyes off the advancing form, which now was only five yards away. With escalating alarm, she noticed that both its hands were concealed. She tried to say something, but her mouth was too dry. Belatedly, she stuck her hand into her anorak pocket, scrabbling for her CS spray. She could now sense someone running full-pelt across the Green, but still at least a hundred yards off.

The figure now stopped directly in front of her, slowly lifting its head, and at the same time drawing one of its hands from under its capacious folds.

But the hand, when it came into view, and which was little more than a curved, bony claw, was empty, and in fact cupped. The face, which was wrinkled and wizened, was familiar to her.

‘Armed police!’ Danny bellowed, as he reached the northern edge of the Green, his Glock drawn and levelled two-handed. ‘Stay where you are! Don’t bloody move!’

‘Danny, wait!’ Lucy shouted, raising a warning hand.

She again glanced at the figure in front of her, at the docile, non-comprehending eyes of Sally Skegg, one of several of Crowley’s resident homeless; a mentally challenged but otherwise completely harmless street-woman. Lucy peered past her and at the distant east end of the terrace saw what looked like a rusty shopping trolley full of discarded cans.

‘It’s okay, Danny! False alarm.’

Warily, he lowered his weapon.

Lucy turned back to the bag lady, who didn’t even seem aware that Tucker was present.

‘God’s sake, Sal!’ Lucy said. ‘You can’t be wandering the streets this late. Not in October. Here …’ She dug into her pocket for some change, and dropped it into the cupped hand.

On the Green, Tucker shoved his pistol back under his jacket. He lifted his chequer-banded baseball cap and scratched under his hairline. There was a screech of gears from somewhere nearby. Ruth Smiley was trying to find a quick way around to them, and by the sounds of it, she wasn’t succeeding. As Sally Skegg glided back towards her trolley, counting her handful of newly acquired coppers, Lucy moved to the barrier to speak with Tucker. Before she did, she glimpsed more movement in her peripheral vision, and looked to the west end of the terrace.