The car park at Hudson and Slack was empty, except for the fire investigator’s van and two police vehicles. There appeared to be no damage to the building at first, as Cooper and Fry drove down the street. The sign over the entrance was intact, and still claimed Hudson and Slack to be a dependable family business. It was only when they parked next to a patrol car that they saw the blackened walls and shattered windows. The parking area was running with water, but it was difficult to tell how much of it was rain and how much was from the firefighters’ hoses.

‘The damage is serious, but confined to the offices and a store room,’ said the fire investigator, brushing soot off his fluorescent jacket. ‘Luckily, the internal doors are all pretty solid and fitted with automatic closure mechanisms. They resisted the flames long enough for the first appliance on the scene to get the fire under control within half an hour or so.’

‘There’s no doubt it was started deliberately?’ asked Fry.

‘None at all. The back door has been forced, and there are indications of accelerant all over the store room. The fire ignited within five or six feet of the doorway. Similar story with the vehicle.’

‘Vehicle?’

He gestured towards the compound behind the building. ‘There’s a burnt-out hearse. Your arsonists smashed the windscreen, chucked accelerant in and torched it. I found the remains of a plastic petrol can on the front seat.’

‘That might be useful.’

The investigator smiled. ‘Plastic doesn’t hold up well in a fire, so it’s just a molten lump. But you’re welcome to it. I doubt Forensics will tell you much, except that it’s green.’

‘Green? What does that mean?’

‘Well, if they were following regulations, the petrol should have been unleaded.’

Two lines of crime scene tape stretched from the building to the fence, and a uniformed officer in a waterproof jacket stood by with a clipboard, guarding the perimeter. There was a cough and a shower of rubble, and a scenes-of-crime officer emerged from the damaged doorway. Cooper saw with pleasure that it was Liz Petty. Well, given current staffing levels, it was a fifty-fifty chance she’d have been called out.

Petty smiled, then looked at Fry and ducked her head to wipe a smear of soot from her face with a gloved hand.

‘No secret about what happened here,’ she said.

‘So we hear,’ said Fry. ‘But no doubt you’ve got a contribution to make.’

The SOCO blinked slightly, but carefully avoided meeting anyone’s eye. She pointed at the fence. ‘That’s the way the offenders entered the property. They cut the fence and came over the wall from the railway line.’

Cooper walked to the wall and looked down into the cutting. ‘There are some industrial units on the other side of the line.’

‘Security cameras?’ asked Fry.

‘A few, but they’re covering their own premises. There’s no reason they should have a camera pointing this way.’