‘That’s not true,’ Yoyo rounded on him. ‘You’re talking nonsense!’
‘But that’s how it looks to—’
‘That has nothing to do with you! Nothing at all, okay? Keep out of my private life.’
Jericho tilted his head.
‘Okay, princess. As far as I can. So what was Tian supposed to do? Slap Hongbing on the shoulder and say, no need to worry? I know something you don’t know. But all right, your private life is sacred to me, even if it’s cost me my car and possibly my flat, which could go up in flames at any moment. You’re causing a lot of stress, Yoyo.’
A wrinkle of fury appeared between her eyebrows. She opened her mouth, but Jericho interrupted: ‘Save it for later.’
‘But—’
‘We can’t go on wasting time on your island for ever. Let’s see how we’re going to get ourselves out of this mess.’
‘We?’
‘You’re not listening, are you?’ Jericho showed his teeth. ‘I’m in this too, so take a good hard look, young lady! You’ve lost your friends. Why do you think all this happened? Because you stirred up a bit of dust? The Party is used to stepping in dissident shit. They might send you to jail for it, but they’re never going to send someone like Kenny.’
Her eyes filled with tears.
‘I couldn’t—’
Jericho bit his lip. He was making a mistake. Blaming Yoyo for the deaths of the others was as unfair as it was stupid.
‘I’m sorry,’ he said hastily.
She sniffed, took a step in one direction, then another, and then sliced the air with her trembling hands.
‘Maybe I should have – I should have—’
‘No, it’s okay. There’s nothing you can do about it.’
‘If only I hadn’t come up with that stupid idea!’
‘Tell me about it. What did you do?’
‘Nothing would have happened. It’s my fault, I—’
‘It isn’t.’
‘It is!’
‘No, Yoyo, there’s nothing you can do about it. Tell me what you’ve done. What happened during the night?’
‘I didn’t want any of that.’ Her lips trembled. ‘It’s my fault they’re dead. They’re all dead.’
‘Yoyo—’
She threw her hands to her face. Jericho walked over, gently took her wrists and tried to draw them down. She pulled back and staggered away from him.
He heard a deep, throaty growl behind him.
What was it this time? He slowly turned round and looked into the golden eyes of an enormous bear.
Very impressive, he thought.
‘Daxiong.’
The bear showed its teeth. Jericho didn’t move. The beast was pretty much as big as a middle-sized pony. Of course the simulation didn’t put him in any danger, but he didn’t know what impulses were emitted by the gloves. They produced haptic sensations, meaning that they stimulated the nerves. Would they also emit pain if the monster decided to start chewing his fingers?
‘It’s okay.’ Yoyo had joined him. She stroked the huge animal’s fur, then looked at Jericho. Her voice was calm again, almost expressionless.
‘We tried something out that night,’ she said. ‘A way of sending messages.’
‘Via email?’
‘Yes. The whole thing was my idea. Jia Wei supplied the method.’
She tapped the bear on the nose. It lowered its head and a moment later it was gone.
‘We’re in touch with a lot of activists,’ she went on. ‘We wouldn’t be able to get hold of the relevant information without them. Of course we can’t openly ask Washington what dirty tricks China’s up to, and I’m registered as a dissident, okay?’
‘Okay.’
‘So, Second Life is one way of tricking Cypol. It always involves a lot of effort. Good for a meeting like ours, but I wanted something quick and uncomplicated, just to send through a photograph or a few lines.’ Yoyo stared at the spot where the bear had stood. ‘And there’s a constant traffic of mails. Boring, unsuspicious mails containing nothing that would scare the Politburo. So we’ve tried to hop other people’s freight-trains.’
‘Parasite mails?’
‘Piggybacks, parasites, stowaways – whatever you want to call it. Jia Wei and I wrote a protocol that lets you encode messages in white noise and decode them again; we used it between Daxiong and me and decided to do a test.’
Jericho was gradually working out what had happened that night. The basic idea was designed to trick even the cleverest surveillance experts. It was based on the fundamental principle of email traffic, which was that mails were primarily a collection of data, little travellers that wanted to be helped on their way. So they were crammed into packets of data like passengers into railway carriages, and like those carriages the packets had a standard length. If one carriage was full, the next one turned up, until there was room for the whole message and it could be sent, with the receiver’s web address up at the front as the locomotive.
But the difference in the quantities of data usually meant that the last compartment was only partly occupied. The phrase end of message defined where the message ended, but because a packet could only be sent as a whole, there was usually some data-free space left over, what was known as white noise. As it arrived, the receiving computer selected the official data of the message, cut the rest off and threw it away. It didn’t occur to anyone to look through the white noise for further content, because there was nothing to be found there.
That was where the idea began. Whoever had it first, it was and remained brilliant. A secret message was coded in such a way that it looked like white noise, was immediately switched for the real white noise and sent on its way like a stowaway. There was only one problem that needed to be solved. You had to send the message yourself, or have access to the sender’s computer. There was no reason not to let stowaways travel on their own trains. But once you’d attracted attention, your email traffic would be under constant surveillance. Organisations like Cypol might be overstretched, but they weren’t stupid, so it was to be feared that they would also check up on white noise.
But there was a solution, which was to use other people’s email traffic. Two dissidents who wanted to pass a conspiratorial message one to the other each needed a router or illegal railway station for passing data-trains, and of course they had to agree on the same train. It might be birthday greetings from Mr Huang in Shenzen to his nephew Yi living in Beijing, both reputable citizens with nothing bad to be said about them as far as the State was concerned. So Mr Huang sent off his birthday greetings without guessing for a moment that his train was about to make an unscheduled stop with Dissident One, who took charge of the white noise, swapped it for the disguised message and sent the train on its way again. But before it reached Yi, it was stopped again, this time by Dissident Two, who received the message, decoded it, replaced it with real white noise, and now at last it went on to the nephew in Beijing, who was assured of Mr Huang’s esteem, while neither of them knew what purpose they had served. The whole thing suggested innocent tourists who had drugs secretly smuggled into their luggage at the airport and then taken out again at the other end, with the significant difference that the drugs didn’t assume the appearance and consistency of their underwear.
‘Of course we weren’t so naïve as to assume that we’d invented the trick,’ said Yoyo. ‘But it’s really not that likely that you’re going to come across an email that already has a stowaway.’