Barnes shook his head. ‘The News Shopper is just a weekly rag. We need the mainstream tabloids and TV involved. I’ve already spoken with our press office. They’ve organised a press conference for four o’clock this afternoon at Orpington where I’ll make a public appeal for assistance. I’ll need blown-up photos of the cross, the coffin and the victim in the coffin.’

‘The anthropologist who does facial reconstruction is making a two-dimensional drawing of the nun’s face. It might be worth using it in a press appeal,’ Jane chipped in.

‘I want to see it first,’ Barnes replied.

‘Are you forming a murder squad, sir?’ Boon asked hopefully.

‘Yes. It’ll be based at Orpington. There’s a conference room we can use. Stanley, I want you to set it up today, so take two more Bromley detectives with you to help. I’ll call around the division and ask them to release further staff. I want everyone at the press conference and a five thirty squad meeting after it.’ He looked at Jane. ‘In the meantime, you speak with Mrs Parkin and Boon with Miss Rogers.’

‘Are you going to arrest Bishop Meade?’ Boon asked.

Barnes shook his head. ‘There’s not enough evidence yet. Even if Meade admits he went to the mortuary, it doesn’t prove anything. Our priority is identifying the nun and finding a connection between her and Meade. Clearly it would take at least two people to move that coffin to where it was found. That said, our only suspect at present is Bishop Meade. But we need to find substantive evidence he has lied and obstructed the investigation before arresting him.’

‘I have an idea where the coffin might have come from,’ Jane said. ‘I was about to tell you before Bishop Meade called. Can I just nip and get a plan of the convent so I can show you?’

Barnes nodded. Jane returned quickly with the 1851 plan of the convent and laid it out on Stanley’s desk as the others gathered round.

‘I spoke with an architect who told me these markings are for a tunnel. As you can see, it runs from the convent chapel basement to the outbuildings.’

Barnes looked thoughtful. ‘It makes sense keeping a coffin in the chapel basement . . . and the tunnel would be useful cover for moving it unnoticed.’

‘Between the convent and the outbuildings are gardens, surrounded by eight-foot-high walls, which give further cover once you exit the tunnel. The coffin was found just here, which is about fifty metres away.’

‘At the time, no one would have thought houses or flats would be built on the land,’ Boon added.

‘If you’re right, Tennison, using the tunnel to move the coffin implies someone living at the convent was involved.’

‘I agree, sir, but there’s also the possibility it could have been a layperson who worked at the convent,’ she said.