‘Can’t find him. Definitely a male voice,’ Tripp said, flicking from camera to camera. ‘The crowd’s too large now. Whoever’s laughing is right in the middle and they’re shielded from our viewpoints.’

‘You make sure she gets down safely and as quickly as possible,’ Ava said. ‘I’m going out to find him.’

‘You’ll have to cover your face, ma’am. You’re too recognisable, especially to some of the people who live round here. You’ve arrested a fair few of them.’

‘Give me your coat,’ Ava said, taking Tripp’s hooded winter jacket and pulling it around her face.

‘You don’t know that whoever’s laughing is the same person who was on the bridge with Stephen Berry,’ Tripp reminded her.

‘Sounds the same to me,’ Ava said. ‘And this might be our last chance to catch him before someone else dies.’

She slipped out through the door, keeping her head down and following the sound of laughter. Pushing past one of the camera crews, she spotted the bookie who’d been taking bets on the outcome of the drama. By the time she got to him, making sure she got a good look at his face for later retribution, the laughing man had moved away, but the noise he was making continued, if anything higher-pitched and more aggressive. Above them, Janet Monroe was continuing her Oscar-worthy performance. The crowd closed around Ava, pushing forwards, desperate to watch, unable to look away.

‘Go on, do it!’ a man shouted from behind her.

By the time Ava had turned to catch a glimpse of his face, he’d gone quiet.

Someone in the crowd booed him and another shouted for him to shut up. Ava appreciated the community spirit but at that moment in time she just wanted everyone to be quiet so she could hear when he shouted again. She did a three-sixty, pulling her hood down so her ears could pick up the sound and direction better.

The laughing began again. It had a hysterical edge to it. All broken glass and chalkboard. Ava tried to make her way between several onlookers, one of whom was trying to climb onto her boyfriend’s shoulders.

‘Just wait a moment, would you, love?’ the man asked her.

‘I need to get through,’ Ava insisted.

‘You’re gonna knock her off. What the fuck’s your problem?’ He pushed his face just inches from Ava’s.

She instinctively reached into her pocket for her ID, then held herself in check, knowing all Monroe’s hard work would be for nothing if she revealed the plainclothes police presence in the crowd. Making herself count to ten, she waited until the girlfriend was safely up in the air and waving like a reality-TV wannabe at the nearest camera operator.