Slack had spent an hour on his laptop and had learned that The Slayer was one of a number of notorious female assassins who were working or had worked for the Mexican cartels.

And from the sound of it they were a right bunch of bloodthirsty crazies. Dubbed Las Flacas (The Skinny Ones), they were now commonplace in the major cartels. They were considered ideal sicarias (hired killers) because they were young, beautiful, reckless, and attracted less attention than their male counterparts.

One glamorous hit-woman known as Juana made headlines in 2016 when, after being arrested, she confessed to having sex with the beheaded corpses of her victims and to drinking their blood.

Others included La Güera Loca, or ‘The Crazy Blonde’ who had appeared in a video posted online in which she’d beheaded a man with a machete. She was currently one of the most wanted women in Mexico.

And then there was the infamous Maria Lopez, or La Tosca – ‘The Tough One’ – who was caught in 2011 and went on to own up to twenty murders.

‘Our girl has more than twice that number of kills to her credit,’ Slack had told Danny. ‘She calls herself Rosa Lopez, but Cruz says it’s not her real name. He says she’s the best in the business but he wouldn’t tell me anything else about her.’

‘I don’t think there’s anything more you need to know, boss,’ Danny had said. ‘For the job you want her to do she sounds fucking perfect.’

10

Rosa

While Slack was holding court in Rotherhithe, Rosa Lopez was just over halfway through her flight to London.

She’d managed a few hours’ sleep, disturbed as usual by the same recurring dream that took her back to that morning twenty-two years ago when she walked into her parents’ bedroom and found them lying on their blood-covered sheets.

She tried to wake them and when she couldn’t she just lay on the bed between them, crying and screaming until Mr Torres from next door broke in and discovered the carnage.

The dream was always so chillingly vivid and it served as a constant reminder of the event that changed the course of her life.

She was told later that her mother and father had each been shot twice from close range by an assassin or assassins who almost certainly used a silenced pistol. It was never established how they’d got into the house in the dead of night, but she did find out why.

Her father had been a drugs dealer for a local gang and had been targeted by his own people who accused him of stealing money from them. In order to make an example of him they decided to kill his wife at the same time.

Rosa was adopted by her father’s sister Teresa and her husband Enrique. But she hardly knew her aunt and had never met Enrique before the day they came to collect her.