There are a few streaks on the floor which might be blood and the tiles, though obviously recently swept, are still grubby in places. That’s good. The forensic boys love a bit of dirt, perfect for catching prints, DNA, all the stuff they like. The curtains flap more wildly. The wind is getting up.

Nelson turns to Henty. ‘Was the window open when you got here?’

‘Yes.’

Strange to have an open window in October. Nelson walks over to it and looks out. They are on the ground floor and it would be fairly easy to get in that way. Outside is the car park, a few dustbins and a charity recycling box. No handy soil for footprints but someone in the adjoining offices may have seen something. He’ll have to send Rocky house-to-house.

Nelson walks slowly round the room. He realises that the patterns on the walls are in fact a series of pictures. Norfolk Through The Ages. One scene in particular catches his eye: a circle of wooden posts on a beach, a crudely drawn figure in a white robe in the centre of the circle, arms stretched out like a scarecrow, an improbably yellow sun shining overhead. Nelson goes closer. ‘Bronze Age wooden henge on Saltmarsh Beach,’ he reads, ‘discovered in 1997 by Professor Erik Anderssen of the University of Oslo.’ And by Ruth Galloway, he thinks. He thinks also of the Saltmarsh, the bleak expanse of wind-blown grass, the treacherous stretches of quicksand, the tide rushing in across the mudflats, turning land into sea – a fatal trap for the unwary. Nothing could be further from the cheery blue and yellow beach scene on the wall. He looks at the next wall. ‘Roman Villa at Swaffham, believed to be part of a garrison town.’ A white-pillared house stands smugly in landscaped grounds, like something from an upmarket housing estate. Nelson frowns at it. He doesn’t like the Romans any better than he likes the Bronze Age idiots. Between the Roman Villa and the henge is a cartoon which could, if charitably interpreted, be said to represent a girl lying on her side. ‘Iron Age girl, discovered in 2007 by Dr Ruth Galloway of the University of North Norfolk.’