Foster landed hard, partly on the wooden frame of the chair. Ignoring the pain, he forced himself up off the ground and towards Saunders, who had fallen a few yards in front of him. Foster grabbed at his legs, but Saunders turned and slashed the sharp blade at him. Foster’s arm sprang back involuntarily when he felt a white-hot slash across his flesh. Saunders threw himself at Keller, grabbing her by the hair and pulling her roughly to him. He put the knife to her throat.

The crowd screamed now, falling over each other to pour through the exits. Foster could see them draining out like sand in an hourglass. As he watched, Saunders slipped a noose of twine from his blazer pocket. He pulled it over Kirsten’s head and twisted it in his fist, holding her close like a human shield, biting into her hair so that she couldn’t pull her head away.

When she felt his teeth in her hair, Keller reacted, leaning forward slightly and then smashing her head backwards with everything she’d got. Even above the noise of the horrified crowd, there was a crunch. Noah Saunders spat angrily and dug the knife under her jawbone. When he looked out from behind her, his lip was split and there was a yawning gap where a couple of his teeth should have been. Blood began to pour down his chin and onto his shirt.

Foster weighed up his options. In the stands, creeping forward in Saunders’ blind spot, a uniformed policeman had drawn a bright-yellow Taser and was holding it steadily with both hands as he vaulted in slow motion over the chairs in front of him.

Foster said, ‘Kirsten, look at me. This is all going to be alright.’

Noah Saunders laughed.

‘I can promise you it’s not going to be alright, Kirsten. Especially for you.’

Foster was suddenly aware that his palm was wet and he looked down to see it slashed from the base of his thumb right across his palm, deep enough to expose sinew and bone. In the corner of his eye he could see the policeman getting closer. All the guy needed was a clear shot. Foster tried to engineer one.

‘Do you think this is what your brother would want?’ Foster asked, hoping the mention of his brother would cause Saunders to react.

Keller looked stricken, as she suddenly realised what all this was about.

‘What do you want from me?’ she said to Saunders, her head tilted backwards from the pressure of the knife under her jaw. ‘I only knew Jake for a few months. I’m sorry you lost him, but it wasn’t my fault.’

‘He loved you.’

‘I never asked him to.’

Foster watched Keller and Saunders, thinking fast. Saunders had killed Rosario, and now he was out in the open, with Keller in his grasp. He wasn’t going to stop. Not unless someone stopped him.