The guard looked from Foster to the other man, then nodded to his two colleagues, who escorted the tout away from Murray Mound towards the exits. Over the guard’s shoulder the big screen was still showing the Centre Court action. Keller looked fine. Composed. The live feed cut to a shot of the scoreboard. Thirty all, first game. Not that the score mattered to Foster any more.

‘Sir, I need to take some details from you.’

Foster snapped back to his situation on Murray Mound.

‘What details?’ he said, already beginning to move towards Centre Court.

‘Whenever there’s an incident,’ the guard said, walking alongside Foster, ‘we have to fill in a log. You have to sign it.’

Foster broke into a jog.

‘I’m sorry,’ he said.

‘I don’t have time.’

The guard got physical, really quickly. He put a restraining hand on the arm of Foster’s jacket and reached to grab his shoulder with the other.

‘I’m sorry, sir,’ he said, ‘but it’s our policy that anyone—’

He never finished the sentence. Foster twisted out of the guy’s grip and kicked his legs from under him. The guard was a mass of muscle, and he fell hard. Foster put a knee between his shoulder blades and then patted him on the back as he faced the ground.

‘I’m really sorry,’ he said to him. ‘But I’ve absolutely got to go. You’ll understand later, trust me.’

Foster pushed up and away, and by the time the guard got to his feet and reached for the radio on his lapel, Foster was out of sight. Another guard tried to stop him at the entrance to the court, but Foster pushed past.

An excited hush descended over the crowd and Foster’s feet scuffed audibly as he made his way quickly towards his seat. He looked at the umpire, perched on top of the green chair, high above the action. Foster could see the livid purple bruise on the left side of his neck. A bruise that could have been caused by being punched hard in the throat.

On the court, Kirsten Keller smashed a forehand just inside the white line for a clean winner and the stadium erupted. But Foster didn’t see it. His eyes were locked, unblinking, on the umpire. Was he the same guy he’d bowled into outside Court 12? He was the right age. The right build. And an umpire would have access to the locker rooms. An umpire would follow the tour around the world.

Game point. Keller cannoned a serve dead-centre. Her opponent smashed it back at her, but the ball drifted wide of the line and the crowd cheered.

‘Game, Miss Keller,’ Noah Saunders said, his voice echoing around the stadium.