The old woman broke off from her muttering and glanced up. Despite looking in his direction, she didn’t seem to see him at all. ‘Beware the red wolf at your door! Beware of false prophets, who come to you in sheep’s clothing, but inwardly they are ravening wolves!’

She returned to her muttering, wringing her hands as if in desperate prayer. ‘You shall know them by their fruits. Do men gather grapes of thorns, or figs of thistles? Even so, every …’

‘Mrs Winters!’ persisted Jack. ‘Where’s Jess?’

His sister’s name seemed to stir something deep in the old woman’s mind, for she stopped dead. ‘Jess? Dearest Jess? Is that you?’

‘No, I’m her brother, Jack,’ he replied, feeling a glimmer of hope at having got through to the old woman. ‘Do you know where Jess is?’

Mrs Winters’ eyes grew wide as full moons, her wrinkled skin turning pale as her whole body began to tremble. ‘Beware the red wolf at your door! Beware of false prophets, who come to you in sheep’s clothing, but inwardly they are ravening wolves! Beware the red wolf … the wolf in sheep’s clothing … You shall know them by their fruits. Do men gather grapes of thorns, or figs of thistles? Even so …’

She repeated her incantation over and over. In spite of further attempts to communicate, Jack could get no sense from the old woman. She was lost to her ravings.

‘Told you she’s crazy!’ said Rose, leaning against the cell door. ‘And who’d blame her? Being locked up for months in a plague house as people slowly died and decomposed all around you. It’s enough to send anyone mad!’

‘What does she mean by “the wolf in sheep’s clothing”?’ asked Akiko.

‘That’s from a sermon in the Bible,’ said Rose. ‘The Gospel of Matthew.’

Jack turned to Rose. ‘How do you know?’

‘I do go to church,’ said Rose, adopting an offended air before a mischievous grin broke through, ‘despite my sins!’

Jack asked Mrs Winters again about his sister, but only got more babbling of scripture. ‘You’re right, Rose,’ he sighed. ‘This is a waste of time. She’s just quoting from the Bible. Even if she does know where Jess is, she’s in no state to tell me. Let’s go.’

As Jack stood to leave, Mrs Winters grabbed his arm, her grip surprisingly strong. ‘Beware the red wolf!’ she hissed as she shoved a small hard object into his hand.

Jack slowly unfurled his fingers to reveal a silver locket. He prised it open. Inside was a tiny watercolour portrait of a young woman with hair like spun gold and eyes as blue as a midsummer sky. Jack instantly recognized her. ‘Jess!’ he gasped.

He took hold of Mrs Winters by the shoulders and shook her. ‘Where is she? TELL ME, WHERE IS JESS?’