Frost nodded. ‘Rumour has it that the Comptons paid close on a quarter of a million for the place. With the slump in the housing market it’s worth a lot less now.’

The car scrunched up the gravel driveway which led to a white-framed, black front door outside which a police car was already parked. Alongside the drive ran a lawn, once immaculate, but now a muddy, churned-up, tire-grooved mess a-slosh with dirty water. Their job done, firemen were clambering into a fire engine ready to drive off. In the middle of the lawn the Fire Investigations Officer, rain bouncing off his yellow sou’wester, was gloomily poking through a jumble of sodden ashes and burnt, paint-blistered wood, all that was left of the summer house. Frost paddled over to him, cursing as water found the holes in his shoes and ruefully remembering his wellington boots snug and dry in the back of the car. Gilmore stayed put on the path. He wasn’t ruining his shoes for a lousy burnt-out summer house.

Frost flicked his eye over the smouldering remains. ‘I could have made a better job of putting it out by peeing on it.’

The fire officer straightened up and grinned. ‘We didn’t stand a chance, Jack. The wood was soaked with petrol. We got here twelve minutes after the call, but it had almost burnt itself out by then.’

‘Petrol?’ Frost picked up a chunk of wet burnt wood and sniffed it. It smelled just like wet burnt wood. He tossed it back on the pile and watched the fire engine drive away.

‘No doubt about it. I’m still checking, but it was probably set off by some crude form of fuse – a candle or something. I’ll be able to tell you more when I find it.’

‘You know me,’ said Frost. ‘If it’s crude, I’m interested.’ He squelched back to the drive.

Gilmore hammered at the front door while Frost scuffed moodily at the gravel path and tried out the rusty bell on an old-fashioned, woman’s bicycle which leant against the wall. The door creaked open on heavy, black, wrought iron hinges and a scrawny, leathery-skinned woman in her late sixties, carrying a mop and bucket, scowled out at them. She wore a man’s cap, pulled right down over her hair, and a drab brown shapeless dress, tied at the waist with string.