‘Oh, Jesus, did you hear that?’ Alice said. ‘The poor man’s wife has only just had a baby. That’s so tragic.’

Indeed it was, Rosa thought. But then tragedy was part of life. Part of the whole goddamn cycle we were all caught up in. It couldn’t be avoided, so there was no point making a deal of it. You just have to move on. Put it behind you. Accept that everything happens for a reason.

It was what they drummed into her after she found the blood-spattered bodies of her mother and father. And it was what she’d believed to be true ever since.

She was back in the hotel room by eleven o’clock. After changing out of last night’s clothes she spent the next couple of hours in her bra and panties going over the notes she’d made the previous day.

She crossed Dave Prentiss off the list of names she’d been given and reminded herself how she intended to approach the next two hits.

At the same time she worked out contingencies, knowing that she would probably have to adapt her plans as she went along. She could no longer predict where her targets would be because now they would all be worried and therefore taking precautions.

She left the TV on, tuned to the news, and nothing she heard gave her cause for concern. And neither did it make her feel guilty. That was a pointless emotion, which in her line of work could not be indulged.

So what if the detective she’d shot had just become a father? She hadn’t known the guy so why should she care?

Plus, it was Roy Slack who bore responsibility for what had happened and for what was going to happen. He had issued the death sentences. She was simply acting on his instructions, upholding her end of the contract.

But she wondered how many killings he’d allow her to carry out before he called a halt. Did he have the balls to let it go to double figures? If he didn’t stop her, and she stayed for two weeks, that would be fourteen hits if she managed one a day, which was, in all honesty, pushing it.

By Mexican standards it wasn’t a lot. The murder rate in Tijuana alone was three a day. A year ago, during the course of just one week, thirty people were executed – ten cops, twelve cartel members and eight soldiers. And it wasn’t uncommon for the authorities there to uncover mass graves where all the victims had been decapitated.

But this was London. Not Tijuana. And not Mexico. And although it was evident that Roy Slack did not have much of a conscience, she wasn’t sure he had enough ice in his veins to let it go too far.