‘You’re an embarrassment to your brother.’ Foster went in hard. ‘If he loved Kirsten, this is the last thing he’d want.’

The goading worked. Saunders stepped out from behind Keller so that he could point at Foster with his blade.

The cop with the Taser took his chance, shouting, ‘Armed Police’, and fired as the umpire spun towards him. But he missed, instead hooking Keller with the high-voltage wire. She stiffened and shook, every muscle in her body pulling taut and convulsing. She toppled backwards, only Saunders’ firm grip on the noose keeping her on her feet. Her eyes bulged and her head twisted awkwardly under the strain.

Saunders pulled her back close to him, shielding himself once more.

‘You fucking missed,’ he spat at the cop. ‘Now back off or I’ll slit her throat.’

The cop did as he was told.

Saunders reached round and ripped the metal wire from Keller’s skin. She screamed, and after a couple of seconds blood began to soak through her white playing top.

‘That goes for the rest of you as well,’ Saunders shouted across the stadium, as he spotted the red dot of a laser skirting across his forearm, and followed the beam up to a police marksman on the roof.

Then he turned to Foster.

‘My brother died because of this bitch,’ Saunders said. ‘And today I’m putting that right. The service box you’re standing in is your world, you understand? Move out of that box and bad things will happen.’

Foster kept his hands by his sides, and felt the blood running fast down his fingers. There was no pain from the cut in his hand or the ripped muscles in his arm. Adrenalin worked better than codeine. He forced himself to breathe slowly as he watched Saunders walk backwards off the court, his sharp knife pressed hard into Kirsten’s throat. The time for anger would be later. Right now he was calm and professional, and he waited with cold-blooded patience for the first sign of an opportunity.

CHAPTER 27

FROM WHERE CHRIS Foster was standing, he could see the whole stadium growing up around him. He could see the last of the seats emptying, as spectators scrambled to safety. He could see Wimbledon staff slowly melting from their exit posts and being replaced by tactical firearms police.

Noah Saunders was tucked in close to Keller, and nobody could take a shot. The TV cameras swivelled as he dragged her across the grass towards the huge scoreboard, which showed Keller’s name in bright-yellow letters. When Saunders stepped off the grass onto the concrete steps of the Centre Court stands, the cameraman nearest him freaked out, stepping back from his equipment and raising his hands in the air. Saunders quickly turned towards him.

‘Keep filming!’ he said.

The cameraman stepped out from behind the camera, his arms raised in surrender.

‘Keep fucking filming!’ Saunders growled.