Maddy scooped up some fries from her box. ‘Anyway, if I can continue, Liam? Chan set out to do a paper on zero-point energy and ended up changing course. Instead he wrote a paper on the theoretical possibility of time travel. The main point he was making in his work was that the theoretical energy that was assumed to be there in normal space-time, the sub-atomic energy-soup that was meant to be everywhere, was in fact a form of “leakage” from other dimensions. He writes this science paper and does nothing else notable until his death from cancer a few years later at the age of twenty-seven.’

‘So, like Foster told us,’ said Liam, ‘this Chan lad is the true inventor of time travel, not the Waldstein fella?’

‘Well, he did the theoretical work that led to Waldstein’s machine, so I guess they’re both responsible for inventing it.’

‘The message from the agency said he’d been assassinated,’ said Sal.

Maddy nodded. ‘Which means… what?’ She looked at both of them. ‘I’m guessing it means someone is trying to prevent time travel being invented?’

Liam reached for a ketchup sachet. ‘So… hold on. Isn’t that what the Waldstein fella wanted in the first place? To make sure time travel never got invented. Isn’t that why this agency thing exists, why the three of us’re here instead of dead?’

‘So why would the agency want us to save Chan?’ asked Sal. ‘I mean

… no Chan means no time travel, right? That means no more time problems.’

‘S’right.’ Liam raised a finger. ‘The message didn’t actually tell us to save him.’

Maddy leaned forward. ‘It was an incomplete message. Maybe that’s the bit we missed at the end?’

‘But we don’t know that for sure,’ replied Sal. ‘Maybe it was someone from the future letting us know that time up ahead was changing and that there was now no more need for the agency… for us?’

Maddy shook her head and pointed to the message printed out on paper. ‘Look… it begins with “contamination event”. I’d say that suggests they considered this to be a bad thing. And they’re not too happy about it.’