Rowan walks over to him, takes a deep breath, the scent of sweat and oranges and burning fill her head. Then she grabs a handful of his hair and drags him over to the Ring Knot. He kicks and screams the whole way until she taps him on the side of the head with the hammer – just hard enough to make him sag and groan.

Then she unties him and fixes him to the stakes. Spread out like a frog in a science lab, waiting for the lesson to begin.

She closes her eyes. Hangs her head. ‘Miserere mei Deus secundum magnam.’

Have mercy upon me, oh God, according to your loving kindness.

Chapter 30

30

The rancid stench of a partial-decomp post mortem oozed out of the cutting room like an unplugged fridge full of raw meat left in the sun. Tuneless whistling joined the smell as Miss Dalrymple – in wellies and a thick rubber apron – hosed the tiled floor, chasing smears of blood down the drain.

Logan tried the viewing room.

Dr Graham was hunched over another resin skull, measuring it with callipers, then consulting a long table of figures. She looked up as he closed the door. Her smile was full of teeth. ‘Just working out the tissue depth markers.’

‘What does “SIA” mean? ’

‘Ah, right.’ She hopped down off her stool and rummaged through a stack of paper. ‘Stable Isotope Analysis. Got the results back from Dundee on that segment of thighbone we sent them. The one from your rooftop skeleton? ’ She handed him a wodge of paper streaked grey down one side where the mortuary printer’s innards were eating themselves.

The report started out with social niceties – how nice it was to hear from Dr Graham again, and maybe they could go out for a drink next time she was in town – then descended into an almost indecipherable wodge of technical speak and wiggly-lined graphs.

Logan frowned at it for a bit. . .

Nope. Not a clue.

He passed it back. ‘Any chance of the short version? ’

‘Well, the fourteen-C isotope analysis bomb-curve dating puts time of death between thirty and thirty-five years ago. Your victim wasn’t recent.’

Thirty-five years ago? Agnes Garfield wasn’t even born then.

‘The thirteen-C and one-eighty stable isotopic composition in conjunction with the eighty-seven-S-R slash eighty-six-S-R isotope ratio and strontium—’

‘The short version, Doctor.’

Pink bloomed on her cheeks. ‘Sorry. To get strontium and one-eighty levels like this your victim had to live north of a line drawn between Montrose and Helensburgh. The thirteen-C data points to a Central European diet, so she wasn’t from the States.’