Confusion crossed his features. ‘Where did you find them?’

‘At the latest murder scene.’

‘They were together?’

‘Yes. Why?’

‘It’s an odd combination, that’s all. They’re a mixture of pagan and occult characters.’ He pointed to the first one. ‘This is a runic sigil of Icelandic origin. It represents the powerful binding of a prisoner or slave. The other two are more traditional occult figures relating to fate and reward.’

Hawkins made sure Aaron was making notes. ‘There was also a pentacle drawn on the floor with candles. Can you tell us what their combination means?’

Byford’s brow creased. ‘It’s ritualistic, certainly, yet they have no specific collective meaning. There are so many interpretations of what different symbols and practices represent. But if I had to guess at what whoever created this scene was trying to achieve, I’d say it was sacrificial.’

‘We reached the same conclusion. But to what end?’

‘Who knows?’ He sat back. ‘Sacrifice is highly subjective.’

She conceded defeat for the moment. ‘Fine. There’s just one more thing I need to ask you about. A member of your organization named John Mardell.’

Byford eyed her. ‘What about him?’

‘How well do you know John?’

‘Not well. He was vetted by a former member who died last year. He attends our gatherings intermittently, but isn’t interested in the group’s social aspect. I don’t think we’ve exchanged more than ten words.’

‘Is he close to any other members?’

‘I wouldn’t have thought so, but that goes with the terrain. A number of our regulars prefer to remain largely anonymous. Why the interest?’

Hawkins decided to level with him. ‘He was at the ritual last night, but somehow he gave us the slip. We need to find him urgently. Anything you can tell us about him will help.’

‘Well,’ Byford appeared to suppress a smirk, ‘much as I’d love to cement our newfound solidarity, Detective, I’m afraid I can’t help you with this one. Like I said, I hardly know the man.’

‘So, you wouldn’t have any idea why he was seen on Cavendish Square two days ago, watching the headquarters of the Paranormal Society, a rival group, shortly after one of their members was killed.’

‘Absolutely not.’ He spread his hands. ‘Now, I assume my unadulterated cooperation will be rewarded.’

‘Of course. But you must appreciate my line of work demands a level of cynicism. It would be rather unprofessional of me to release you without corroborating your answers, don’t you think?’ She watched his face fall. ‘Let me speak to a few of your fellow group members, and if everything tallies, we’ll see about getting you charged and released after the statutory twenty-four-hour period, OK?’