In front of the homeless man was a steaming mug of tea, along with a plate of custard creams, which he was industriously munching his way through. He was looking around the room suspiciously, shifting uncomfortably on the chair, as if he was now beginning to regret coming here. She knew that as a witness he wasn’t actually compelled to attend and was free to leave any time he wanted, though how far he was aware of that right now was another matter.

‘They initially noticed him on public CCTV,’ said Dale. ‘So they knew he was there when the bomb went off. But it took them a while to track him down. They promised him a hot cup of tea and a biscuit and he was happy to come in. They thought it better to bring him into the station so they could record the statement.’

‘Please state your full name,’ said DS Blake.

‘Dave Boakes,’ said the homeless man after a short pause. Bailey detected a regional inflection in his voice. Bristol perhaps.

‘What’s your place of abode?’

Bailey rolled her eyes. ‘Seriously…?’

Dave smiled at the question. ‘I like to move around. But I would say my main place of abode is currently underneath the Westway.’

The Westway was a large elevated road leading into London from the West of England.

‘I like West London,’ he added, picking up another custard cream. ‘You get a better class of person around there.’

‘Can you tell us what you were doing in Chiswick the evening that the bomb went off?’ said DS Charles.

‘I was just sitting there in a doorway, trying to keep warm. As you do.’

‘Can you tell us what you saw?’

‘I didn’t see anything,’ said Dave, swallowing the biscuit.

‘Nothing?’

He shook his head. He looked at the empty plate in front of him. ‘Got any more biscuits?’

‘When you tell us what you saw.’

‘It was kind of dark. Couldn’t see much. And it was cold. Very cold.’

‘You must have seen something,’ said Blake.

‘We’ve got you on CCTV talking to the victims,’ Charles added. ‘What did you talk to them about?’

‘I asked him if he had any spare change and he gave me fifty quid.’ Dave smiled proudly.

Blake raised his eyebrows. ‘Fifty quid? That’s generous. What did you buy with it?’

Dave scratched his head quizzically and a perturbed frown settled on his face. ‘I don’t remember.’ He glanced around the interview room. ‘I don’t like this place. I want to go now.’ He crossed his arms and sat there with a sullen expression.

The two detectives looked at each other and sighed.

Dave scratched at a sore on his neck. As he did so, the cuff of his grubby coat fell aside to reveal an incongruously flashy watch.

‘That’s a nice watch you’ve got there,’ said Blake.

Dave glanced down at his watch and cupped it defensively against his chest. ‘It’s mine,’ he said.

‘That’s a Rolex GMT, if I’m not mistaken,’ said Charles. ‘They cost at least ten grand and I hear there’s a three-year waiting list if you want to get a new one.’