Instead of driving into central London, she noticed that they were in fact on the A12 heading eastwards out of the city in the direction of Essex. At that point a bad feeling began to gnaw at her.

‘Just got to make a little detour first,’ was the answer when she casually enquired where they were going.

If a problem arose while she was working undercover, she would send a coded text message to her police colleagues to let them know that something was up, and if need be they could triangulate her position from her mobile phone signal.

She reached into her bag. But her phone wasn’t there. A bolt of alarm shot through her. She rooted further. It definitely wasn’t in there.

‘Lost something?’

‘My phone.’ She sighed, playing ditzy. ‘Silly me. Must have left it on my desk.’

But she knew they must have taken it from her bag when she wasn’t looking. They were one step ahead of her. Something was definitely up.

But she couldn’t afford to panic, or to show any kind of fear. That would have given the game away for sure. So she sat there, quietly trying to anticipate, with a mounting dread, what lay in wait for her when they reached their final destination.

The traffic thinned out as they entered a bleak industrial estate situated just beyond the north-eastern outskirts of the city – big grey warehouses, empty units, vacant weed-strewn lots… and the location of one of their scrapyards.

The scrapyard had big concrete walls with broken bottles set into the cement along the top. The metal gate rolled back to let them in and then clanged shut behind them. The place was filled with stacks of rusted cars, towering five or six high – write-offs destined for scrap. All around, among the dirty puddles in the pitted ground, lay bits of engines and other car parts. Over to one side was a row of grim-looking concrete workshops, outside of which were two huge, slavering Rottweilers chained to a metal post.

It was when the car stopped that they started on her. Within the tight confines of the vehicle, they grilled her relentlessly, two in the back on either side of her, and two in the front, all of them aggressively firing questions and accusations at her.

They alleged that she was an undercover cop, claiming they had it on good authority from a source inside the police who’d tipped them off to her presence. But whether that was true or whether they were bluffing, she wasn’t going to admit that she was anything other than an innocent secretary.

Never break cover. Whatever they might say. Whatever they might claim.

Never. Break. Cover.

They knew an informant must have been involved in her infiltration and they wanted to know who this traitor was. They wanted her to give up Spyros. But she couldn’t afford to do that. She denied all knowledge of what they were talking about.

But these weren’t the kind of people who took no for an answer.