Rowlinson looked up from the iPad for a moment and held Priest’s gaze. ‘It would help if, confidentially, you could tell me whether Alexia Elias was actually taking bribes from terrorists or not. That would cut out a whole layer of investigation and I don’t know whether you caught the Home Secretary’s recent ramblings but the Met’s in for another round of cuts.’

‘Tiff, if I could help on that front then . . .’

‘Oh, come on, Priest! I’m doing my own fucking photocopying at the moment!’

Priest held his hand up in what he intended to be a conciliatory gesture. Rowlinson’s outburst was a surprise – the detective was always calm under pressure.

‘The simple fact is this: I don’t know,’ Priest concluded.

Rowlinson ran a slightly quivering hand through his hair. ‘What do you mean, you don’t know?’

‘I’m running a libel trial. Defamation cases are concerned with evidence, not truth. If those two things happen to align then it’s nothing more than a happy coincidence.’

‘Or an unhappy one.’

Priest said nothing.

Rowlinson carried on. ‘Well fine, I’ll put it in your language then. What were the chances of the court coming to the view that Simeon Ali was telling the truth, were he still alive?’

‘Sixty per cent, maybe fifty-five. But it’s not going to help you, Tiff. I’m working to a much lower standard of proof than you. I have to show that, on the balance of probabilities, The Real Byte’s article was justified, in other words there was a fifty-one per cent chance or more it was true. If I had to prove everything beyond all reasonable doubt, I’d have packed up eighteen months ago.’

‘I really hate lawyers, Priest,’ Rowlinson grumbled.

‘I know.’

‘Let’s try you on something else then.’

Rowlinson swung the iPad around to face Priest and propped it up using a stapler from the end of the desk. The image was a paused video – Priest couldn’t make out what.

‘Yesterday, there was an incident on the A3, the dual carriageway that runs in and out of London.’ Rowlinson pressed PLAY and Priest realised the view was from the inside of a vehicle travelling in the middle lane. His stomach knotted and he bit the inner part of his lip – he knew what was coming. ‘The picture’s from a prison officer’s dash cam. Dangerous game those boys are in so the Prison Service give them two pieces of travel advice: never take the same route home and always have the dash cam on. The file was recently uploaded to YouTube. Now if you just watch this for a few moments . . .’