‘You’re supposed to have a delegate badge to get in,’ he explained. ‘But just show a warrant card or something. I’m sure it won’t be a problem.’

They were close to the main demo now. There was background music through a portable PA, a song about whales, or maybe it was Wales. Rebus recognised the vocal style: The Dancing Pigs. People were shoving flyers at him. He took one of each and thanked them. A young woman was pacing in front of him like a caged leopard. She controlled the megaphone. Her voice was nasal and North American.

‘Decisions made now will affect your children’s grandchildren! You can’t put a price on the future! Put the future first, for everybody’s sake!’

She looked at Rebus as he passed her. Her face was blank, no hate, no recrimination, just working. Her bleached hair was rat-tailed, threaded with bright braids, one of which fell down the middle of her forehead.

‘Kill the oceans and you kill the planet! Put Mother Earth before profits!’

Rebus was convinced even before he reached the door.

There was a bin inside, where the flyers were being dumped. But Rebus folded his and put them in his pocket. Two guards wanted to see ID, but his warrant card, as predicted, was effective. There were more guards patrolling the concourse – private security, uniformed, wearing shiny caps which meant nothing. They’d probably had a one-day crash course in menacing pleasantry. The concourse itself was full of suits. Messages were being relayed over a PA system. There were static displays, tables piled high with literature, sales pitches for God knows what. Some of the booths looked to be doing good business. Minchell excused himself and said he’d meet Rebus at the main doors in about half an hour. He said he had to do some ‘schmoozing’. This seemed to mean shaking hands with people, smiling, giving them a few words and in some cases his business card, then moving on. Rebus quickly lost him.

Rebus didn’t see too many pictures of rigs, and those he did see were tension legs and semi-submersibles. The real excitement seemed to be FPSOs – Floating Production, Storage and Offloading Systems – which were like tankers, but did away with the need for a platform altogether. Flowlines connected straight to the FPSO, and it could store 300,000 barrels of oil.

‘Impressive, isn’t she?’ a Scandinavian in a salesman’s suit asked Rebus. Rebus nodded.

‘No need for a platform.’

‘And easier to scrap when the time comes. Cheap and environmental.’ The man paused. ‘Interested in leasing one?’

‘Where would I park it?’ He walked off before the salesman could translate.

Maybe it was his tracker’s nose, but he found the bar with no difficulty and settled at the far end with a whisky and a bowl of nibbles. Lunch had been a petrol station sandwich, so he tucked in. A man came and stood next to him, wiped his face with a huge white handkerchief and asked for a soda water with lots of ice.