Page 133 of Stolen Ones

‘Threeo’clock,’ Penn said.

‘What the…?’

‘In relation to Paula, Grace is north-east and she’s south-east of Helen. So we’ve narrowed it down to this five-mile-square area from Belbroughton down to Bromsgrove to Alvechurch back up to Rednal.’

That was still a chunk of area.

Kim looked at Stacey who appeared to be on the phone with Sophie from Land Registry.

She covered the mouthpiece. ‘Doing a reverse search right now.’

The square around the area Penn had drawn on the map was approximately twenty per cent residential, with the balance being rural. There were more than a hundred wooded areas within the scope, and any one of them could have properties hiding within them.

‘Get the forensic botanist on the phone,’ she said to Penn.

He called Ridgepoint as Stacey continued talking and Alison watched something on the playback.

‘Sharon Bairden, how can I help?’ said a pleasant voice on loudspeaker.

Penn gave the background of the case.

‘I’ve not had a chance to carry out a full analysis of the sample but there’s everything you would expect to find: road dirt, soil, oil deposits, petrol, cigarette ends, gravel.’

‘Is there anything you can tell us about the soil? Anything that would help us pinpoint a location?’

‘Well, there is one thing. I’ve found a tree seed, and there may be more. It’s distinctive because it lives on a catkin which looks like a caterpillar. This particular seed comes from theBetula pendulatree which—’

‘English name, Sharon,’ Kim said.

‘Sorry, to you guys that’s the silver birch tree.’

Penn was scanning the aerial view of the search area. ‘What am I looking for?’

‘The silver birch grows anywhere from fifteen to twenty-five metres, with a slender trunk. The tree has an open canopy which lets light through, allowing mosses, grasses and flowering plants to grow beneath them. It needs plenty of light and does best in dry acid soils.’

‘Sharon, anything you can—’

‘Look for white trunks. They’re easily visible through the light leafage.’

Penn zoomed in on something that looked promising, but there was no property anywhere nearby.

‘We’re struggling here, Sharon. Can you give us anything more?’

‘So far I’ve only found one of them. If I don’t find many more, then it’s not the actual trees you’re looking for.’

‘Come again,’ Kim said.

‘If the tyres had been amongst the trees themselves, I’d expect to find at least another dozen. If not we’re looking at a deposit.’

‘Of what?’

‘Not of what. By what. Birds.’

Kim and Penn looked at each other.

‘Birds will use almost anything to make nests. There’s every chance a seed could have been attached to a particularly good twig.’

‘But how does that help us?’ Kim asked.