Macmillan picked up on a few muttered expletives at the other end of the phone. ‘Are you all right?’ he asked Steven.

Steven ignored the question and asked, ‘Did Charlie have anything else to say about the deaths?’

‘Quite a bit, none of it good. Hausman was tortured. Acid was involved.’

Steven screwed up his face as the horror levels kept rising. ‘So Khan wanted something... or wanted to know something... but he’s Pakistani Intelligence; he knows what’s been going on,’ he argued.

‘Maybe not everything,’ said Macmillan. ‘Pakistan’s a mess. No one knows who to trust in government. The political parties loathe each other and no one’s sure what the army has in mind. The intelligence services are fractured and probably pursuing their own agenda while the Americans are reluctant to tell them anything they don’t have to know. That’s how they got to Bin Laden. There are those who say if the Pakistani government had been told in advance of the operation, Bin Laden would have disappeared like snow in July.’

Steven nodded and took everything on board. ‘So it’s possible Khan knows something but not everything.’

‘But he wants to know everything... badly.’

‘And Liam?’ Steven asked in trepidation.

‘It’s cold comfort I know but there was no sign of torture.’

Steven was ready to snatch at any crumb of comfort that was offered. ‘Good,’ he said. ‘Khan must have accepted that Liam didn’t know anything...’

‘Possibly, or maybe Liam appeared on the scene later, maybe even by accident, by which time Hausman had told Khan what he wanted to know,’ suggested Macmillan.

Steven wanted to embrace this suggestion with all his heart — the idea that Liam had gone into the lab for some reason unconnected with this whole sorry business — maybe something to do with his research — and had come across Khan and Hausman by accident was exactly what he wanted to believe but... There was always a but... ‘You said Dan Hausman was tortured. Did Charlie say... how badly?’

‘He was a real mess. His face was practically unrecognisable according to Charlie.’

‘So he must have held out for quite some time... or couldn’t tell Khan what he wanted to know... because he didn’t know himself... and Khan didn’t believe him.’

Both men imagined this nightmare situation for a few moments.

‘Charlie said the bodies were discovered during a routine security patrol in the small hours,’ said Macmillan. ‘By that time, Khan was long gone. That suggests he wasn’t interrupted during his interrogation. The fact that he executed both men at the end of it suggests strongly that he did get what he wanted.’

‘Unless of course, it was Liam who disturbed him and panicked him into giving up and leaving?’

Macmillan knocked that idea on the head. ‘Charlie says both men were found tied to chairs in a small office. He’d been questioning both.’

‘Okay, so he wasn’t disturbed,’ said Steven, sounding resigned.

Macmillan read his mind. ‘I think we have to accept that Khan now knows what we don’t.

Steven took this as a gentle reminder that he focus on the matter in hand and not dwell on things he could do nothing about like Liam’s death and how much he might be to blame. He took a deep breath and said, ‘We’ll need copies of the PM reports, particularly ballistics. We can ask Le Grice in Paris to check them against the bullet used to kill Aline Lagarde.’

‘Let’s get a couple of hours sleep,’ said Macmillan.

Steven knew this was not possible in his case. He made some strong coffee and went over in his mind all that had happened. The flat was quiet, deathly quiet, a bit like the mortuary that Liam Kelly’s body would be lying in, a cold, white sheet covering the unruly red hair and the face that had smiled so much in life. Awful, absolutely bloody awful but, at least, he hadn’t suffered the hellish torture that Hausman had been put through... because... because... Steven ran through the possible reasons for this again... Liam was a student; he wouldn’t know anything about any top secret work going on in the lab... Hausman had finally broken and told Khan what he wanted to know... No, no, no, this was all wrong. Oh, so wrong.

‘Oh Christ,’ murmured Steven as the truth dawned on him and sent a chill down his spine. Hausman hadn’t told Khan what he wanted to know, Liam had. It wasn’t information Khan had been after; it was the disk and encryption key that Simone had sent. The disk had nothing to do with ‘vaccination schedules’ — that’s why it had been encrypted in the first place. Khan knew what was on the disk but no one in the North lab did and no one in the North lab knew that the encryption key existed. They had dismissed the disk as being damaged or irrelevant or both. The only person who knew that the disk was encrypted and who had the key was Liam. The bottom line had to be that Liam had told Khan he had the key.

Twenty four