‘I thought so. I need you to listen carefully, because this could have a direct bearing on everything we’re going to be working on here.’

If Luke had thought he might use this journey to catch up on his mounting sleep deficit he quickly put that thought aside. For the next two hours Jenny took him on a terrifying journey, starting with how, during the Cold War, Soviet scientists had managed to weaponize smallpox, anthrax and a disease called tularaemia, eventually loading these lethal germs in powder form into the warheads of intercontinental ballistic missiles, all aimed at the most densely populated Western cities, including London.

‘Ever heard of a place called Vozrozhdeniya Island?’ she asked, as the damp March landscape of Berkshire flashed past the window. He shook his head. ‘It means “Rebirth Island”. It’s an island on the Aral Sea in southern Russia – or at least it was before the Aral Sea practically dried up. It was where they shipped in hundreds of monkeys from Africa, then exploded chemical and biological bombs upwind of them to study the effects.’ She stopped. ‘Luke, you’re frowning?’

‘No shit I am. That’s horrendous.’

‘Well, it gets worse. There were some human casualties too. On one of their programmes a scientist got a fatal needlestick injury. He pricked his thumb while he was working with Marburg. He took three weeks to die. Painfully. Then as recently as 2004 a researcher died in Siberia after pricking herself with Ebola.’

He could see she was looking at him quizzically, studying his face for a reaction.

‘You don’t know what Marburg is, do you?’ she said.

‘A virus? Named after a town in Germany.’

‘Spot on. Marburg is a particularly nasty haemorrhagic fever, like Ebola. Which means your organs start dissolving and you end up bleeding from every orifice. It’s sometimes been described as “human soup”.’

Luke grimaced and she noticed.

‘I know,’ she said. ‘Not pretty, right?’

Luke held up his hand to stop her before she continued with her catalogue of horrors. ‘Okay, hang on,’ he said. ‘Let me get this straight. I’ve read the report from Svalbard and the guy who died up there – Yevgeny – he was bleeding from the mouth and nose. So does that mean—’

‘That he was infected with a haemorrhagic fever? No, not necessarily, it could still be other things. But you’re thinking on the right lines.’ That was the second time today someone had said that to him. Perhaps this was the intelligence community’s way of saying, ‘Noted, but I disagree with you.’

Jenny sat back in her seat and turned to the window. They had crossed into Gloucestershire now and the River Frome was running parallel to the train line. There were flooded fields on both sides and half-submerged fence posts. Clouds scudded across the sky, threatening more rain.