Foster walked between all of them, getting a feel for distances and lines of sight. He scoped the kiosks and the souvenir stores, and the pinch-points where thousands of bodies would make it impossible to pass. He looked for shortcuts through buildings and across the courts, so that if they needed to move quickly he’d know where to go. He was almost done when his phone buzzed. An alert from Keller’s new alarm. Most likely she was testing it, but Foster wasn’t going to take any chances.

He ran directly for the locker rooms, vaulting the security barrier and barrelling down the players’ corridor, before slamming through the entrance to the women’s locker room.

‘Kirsten?’

No answer.

The locker room was a modern facility: clean white walls and a maze of stained-pine benches and lockers. Plenty of corners that he couldn’t see. Plenty of places to hide. Apparently Keller had taken a while in the shower, because the room was steamy and humid. She answered on his second call.

‘Over here.’

He followed the voice into the labyrinth and found her in an alcove surrounded on three sides by square pine lockers and directly under a set of impossibly bright halogens, which sent tunnels of light through the misty air.

‘What happened?’

She looked back over his shoulder and he turned to follow her stare. Between two banks of lockers was a mirror, which stretched from the floor to the ceiling. Written in tall letters in the condensation were the words ANY TIME I WANT. The writing was fresh. The bottom edges of the letters were just beginning to run, the way blood trickles from the movie titles on old horror billboards.

Foster moved through the room methodically. He checked every corner and every alcove. He ducked in and out of the showers. When he was certain they were alone, he came back to her and they sat down in the steam.

‘Do you think it’s a woman?’ Keller asked. ‘Considering where we are, I mean.’

Foster looked around the locker room.

‘I’m in here,’ he said.

She couldn’t argue with that.

‘Can you tell anything from the writing? You know, like whether they’re left-handed or how tall they are?’

‘I don’t think so,’ Foster said. ‘Not for sure.’

‘Jesus Christ!’ she whispered. ‘He could have grabbed me. He could have done anything.’

She shuddered and pulled her towel a little closer around her.

‘Try not to get scared until there’s something to get scared about,’ Foster said, his eyes calm as they looked into hers. ‘Someone drew in the steam. Nothing more, nothing less.’

She looked sceptical.

‘Take a breath. You said it yourself: whoever was in here had the perfect chance to hurt you. And they didn’t take it. This is good news.’

He smiled and she smiled back, and he felt guilty because he wasn’t sure he believed what he was saying.