After putting the rest of his purchases away in the garage, Nguyen sat at his table and crossed off the list everything he’d already bought. There were three items left: two kinds of acid and glycerine. He knew how to make the acid he needed from other quite innocuous and easily available materials. It was messy, but possible, but there was no need because this was England not Vietnam and here there were firms where you could buy chemicals, no questions asked. He took a well-thumbed copy of Yellow Pages and looked up Chemical Manufacturers and Suppliers. After three calls he had found one firm who would supply him with concentrated acids (for etchings, he’d said) and he arranged to collect a gallon of glycerine from another firm. Nguyen thought it prudent not to buy all three from the same supplier.

Fisher stopped the car and switched off the engine and the lights, allowing the darkness to envelop them like a shroud. He and O’Reilly waited until their eyes became used to the blackness, listening to the clicking noises from the engine as it cooled. They were parked at the end of a lonely lane not far from Bexley station, half and hour’s drive south-east of central London. Both men were dressed in dark pullovers, jeans and black shoes, outfits that wouldn’t stick out at night but which didn’t obviously mark them out as burglars. If they were unlucky enough to come across the police then they’d just pretend they were a couple of queers looking for a bit of privacy. That had been Fisher’s idea, and O’Reilly hadn’t been exactly bowled over by it.

‘Look, I promise not to kiss you,’ Fisher had joked.

O’Reilly had laughed nervously.

‘Not on the mouth, anyway . . .’ O’Reilly had winced and Fisher knew he’d hit a nerve so he let the joke drop. He mentally filed O’Reilly’s over-reaction for future reference, a possible weak point. Fisher did that with everybody he came into contact with, memorising their strengths and weaknesses and the buttons that had to be pressed to get the desired responses.

‘Are you right?’ he asked O’Reilly.

O’Reilly nodded. They got out of the car and Fisher led the way, climbing silently over a stone wall and walking across the dew-laden grass. O’Reilly’s foot knocked against something hard that crunched and rolled, and then he heard a rustling noise behind him, something small scamppering through the grass and making snuffling sounds. Hedgehogs, he realised. There were dozens of them, rolling into tight, spiked balls whenever they sensed the two men.

They reached another wall, this one taller than the first, and they had to scramble over. It surrounded a graveyard, close-clipped grass and gravelled paths, the gravestones a mixture of old stone crosses, chipped and weather-worn, and new, clean-cut marble. To their left was a grey stone church with a steeple. In the distance a vixen barked, and her call sparked off a cacophony of howls from dogs in the nearby housing estate. The two men dropped down into a crouch, their backs against the wall, while Fisher got his bearings.