‘It’s Solomon Stein junior. His father bought the freehold. Dead now. Junior’s all about the money, but he says he’s got clauses in his contracts saying he can sell the freeholds. He doesn’t need to torch any of them.’

‘Sounds like we can rule him out then.’ There was still no sign of the foreman. ‘Dan and I will be here for a while so can you and Shen question Agnieszka and her husband? Make sure Agnieszka stays with her mum afterwards. Jackie’s going to interview Artem. Shake him up a bit.’

‘Sure.’

‘Before I go, any developments on our UnSub or Ali?’

‘Negative.’

‘OK. Dan’s arriving now. Keep me posted.’ I rang off and walked along Stepney Green Road where Dan was getting out of the car.

We talked as we approached the site entrance.

‘I got Shen to pull up some research on the Manor House,’ he said. ‘It seemed a bizarre place to have a farm until I read the history.’

‘My niece adored Stepney Farm when she was younger.’ It was a neighbourhood I knew well, only a few miles east of where I’d grown up. ‘Such a shame that they’ve plonked the development here though.’ I took in the pretty village church of St Dunstan’s, and the local secondary school, Sir John Cass Redcoat. ‘When they floated the plans for these apartments, lots of locals were furious.’ We’d arrived at the site entrance now. ‘I wonder why the killer decided to leave the body here?’

Dan was paraphrasing from his email, momentarily oblivious of my question. ‘. . . built on the grounds of an old Tudor manor house . . . some of the farm-land wasn’t being used . . . so presumably developers spotted an opportunity?’

One implication of working with a detail-obsessed newcomer to London was that he filled in all my knowledge gaps, whether I wanted it or not. I surveyed the red cranes, the hoardings, the high-tech machinery and warehouses, and said loudly, ‘This place is crawling with CCTV. Isn’t it?’

‘Sorry. Yes.’ Dan stuffed his mobile in his pocket. ‘That should make our lives easier.’

‘Thank God there’s no media yet.’ I knew we had minutes before they arrived. ‘The red tops are going to have a field day with this.’

Outside the hoardings, at the crime scene perimeter, a uniformed officer was guarding the site. A man in a fluorescent jacket was charging towards us at the entrance. Beneath his hard hat, he was red in the face and veins bulged in his neck. ‘How long is this going to take?’ He addressed his question to Dan. ‘We’ve got equipment arriving today.’

‘As long as it takes, I’m afraid,’ I said quietly. ‘DI Rahman, Senior Investigating Officer. This is DS Maguire.’ I watched him absorb his faux pas and we both showed him our warrants.

‘You are?’