Next she looked at a document titled ‘Drug industry value by country’. Scanning down, she read that a conservative estimate of the value of the global illegal drug industry was around $360 billion, half of that generated in South America, with cocaine coming in at $130 billion alone, and heroin at $110 billion. In the 2000s, ninety per cent of the cocaine coming into the US was from Mexico. It was calculated that $64 billion worth of illegal drugs went from Mexico to the US annually. Kelly noted with dismay that Afghanistan had supplied a staggering ninety-three per cent of the world’s heroin in 2014.

Next she read about the GDPs of the major drug-producing countries and realised that the global illicit drug trade kept economies afloat. Somewhere in her memory she already knew that, but now it seemed important.

A World Health Organisation report from 2015 drew a bleak and depressing picture of the face of global addiction and what the richest countries on earth were doing about it. She stopped reading. Of course a pharmaceutical giant such as Ravensword would be interested in all of this. She felt foolish. Her shoulders hurt and she had a feeling she was going around in circles, but she read on. This morning Matt had given her twelve hours to find something tying the Montague Club men together. So far she’d found nothing.

She opened another file. It was another WHO document, this time from 2016, but she noticed that it was addressed to DEFRA and the Department of Health. She looked up the names of the relevant secretaries of state and their senior civil servants and jotted them down. A series of diagrams stared back at her and she considered closing the file without further investigation, but the way they were set out, as well as the handwriting accompanying them, made her stop. She’d seen the formulas before: yesterday, when Rob had been updating her on the USB found in George’s car. She poked her head around the door of the incident room and asked him to bring up the scientific calculations they’d sent off to be examined. They matched. She had something linking Tooting to George, but then he was his employer, so it still proved nothing.

She went back to her screen and found herself staring at a remittance payment. It was from a private Ravensword expense account, signed by Tooting, paying an outstanding mortgage with the Halifax. Kelly squinted. She was sure it must be an anomaly. She checked again: it was definitely a residential mortgage for £375,000 on an address in Wiltshire, in the name of Benjamin Dansford. Butterflies vibrated in her stomach.