The trees in the park still had most of their leaves, and the street was narrow and shaded and smelt of wet grass rather than the busy cement smell you get in the rest of the City. The office was based in a Mid-Victorian pile whose Florentine flourishes were not fooling anyone but itself. There was a brass plaque by the door engraved with ‘Public Policy Foundation’ and beyond the doors a cool blue marble foyer and a young and strangely elongated white woman behind a reception desk. Because it’s not good policy to, we hadn’t called ahead to make an appointment. Which gave Guleed a chance to tease the receptionist by not showing her warrant card when she identified herself.

The receptionist’s expression did a classic three point turn from alarm to suspicion and finally settling on professional friendliness as she picked up the phone and informed someone at the other end that the ‘police’ had arrived to talk to Mr Chorley. We agreed later that while she’d lost points for the hesitant way she’d identified us as police, it was good effort overall.

‘Definitely in the top half of the leaderboard,’ said Guleed while we were waiting for someone to show us upstairs.

Martin Chorley’s office was carefully designed to be unpretentious with varnished floorboards, mismatched throw rugs, a John Lewis leather sofa set and a glass-topped desk which I happened to know came from Ikea because I’d considered getting it for the tech cave.

Chorley himself was my height, generally slender but with a spare tyre that was going to see him spending much more time in the gym in future. His hair was dark brown and conservatively cut, his eyes a pale grey and closely set. Judging from the rumples he was wearing yesterday’s suit trousers – no time to change – but a fresh pale blue shirt with packing creases. Mint in its wrapper, I guessed, and kept in the office for emergencies.

He offered us coffee and we declined. Generally you only accept a beverage if the subject is going to make it themselves – creating a sense of normality – or if you’re going to make it, giving you a good chance to snoop around their kitchen. He himself scooped up a bottle of Highland Spring from his desk and waved us onto the black leather sofa while he lowered himself carefully into the matching armchair. His face, I saw, was grey and there were smudges under his eyes so I started gently enough – explaining that this was a routine follow-up interview, blah blah blah, and got about half a sentence in before he cut me off.

‘I heard you made an arrest,’ he said. He spoke with that deliberately toned down posh accent that, before they allowed regional dialects on the radio, used to be known as BBC standard.