Nguyen nodded thoughtfully. ‘I do understand. But if you do not know who the men are, you can surely find out. I want you to find out for me.’

Hennessy shook his head, amazed at the man’s audacity, or stupidity. Nguyen took the pack of cigarettes and the matches from his pocket.

‘Can I smoke?’ he asked Hennessy. Hennessy nodded and Nguyen held out the pack to him, offering him one. The lawyer refused and watched as Nguyen lit a cigarette and inhaled deeply. Hennessy noticed how steady The Chinaman’s hands were, as steady as the unblinking brown eyes that seemed to look through his skull as easily as they penetrated the wreathes of smoke.

‘You will change your mind,’ said Nguyen, and it was a statement, not a question.

‘No,’ said Hennessy.

Nguyen smiled, and it was the smile of a man who has the sure and certain knowledge that he is right. He stood up and bowed once to Hennessy and then left the office. Murphy and Kavanagh were waiting for him outside, and they gave him his carrier bag and the penknife. He thanked them politely and turned to Beth and thanked her as well.

‘Can I use your toilet?’ he asked, and she told him there was one in the corridor outside. She pointed at the large sheet of glass at the entrance to the reception and through it he saw the door with ‘Gentlemen’ on it. He thanked them all again and left the office, closing the door quietly behind him. The washroom was small with whitewashed walls and a black tiled floor. There was a wash-basin, a urinal and a toilet in a cubicle. There was a mirror screwed to the wall above the basin and by the door was a paper-towel dispenser and below it a large steel wastepaper bin.

Nguyen entered the cubicle, shut the door and locked it. There was a black plastic lid on the toilet and he closed it and then sat down, placing the carrier bag gently on the floor. He took one of the bottles out and held it between his knees. It contained the antifreeze. He took out the second bottle, the one containing concentrated sulphuric acid. He used the Sellotape to bind the bottles together, wrapping it round and round until he was certain they were secure. He took out the length of string and tied it around the necks of the bottles, making quite sure there was no way it could slip. Individually the bottles of liquid were inert, but together they were very dangerous. He put the bottles on the floor and draped the string over his left leg. He took the box of matches out of his pocket and slid the string through it. He pulled the string to check that it was safely tied and then put his hands under the bottoms of the bottles and stood up slowly. The cistern was high up on the wall and Nguyen stood on the toilet seat to attach the string to the lever which operated the flushing system. When he was sure it was secure he carefully removed his hands. The bottles turned slowly in the air above the tiled floor. He unscrewed the caps from the bottles and slipped them into his pocket. Then he pulled the filter off the cigarette and stuck the frayed end into the matchbox so that the burning tip was about three-quarters of an inch beyond the match heads. Nguyen stepped down, picked up the carrier bag and left the cubicle. He used the penknife to slide the lock closed so that it showed ‘Engaged’.