'So you and your assistant arrived here and pushed the trolleys to the apartment?'
Mr. Yin nodded. 'I went through all this with Inspector Kwok.'
They walked to the door of the apartment. 'Do you have the key, Inspector?' asked Inspector Zhang. Inspector Kwok produced the brass key and Inspector Zhang nodded at the mat. 'If you would be so good as to put it where it was that day.'
Inspector Kwok put the key under the mat and then stood up.
'Now, proceed exactly as you did on that day, Mr. Yin.'
'But I don't have the trolley so it cannot be the same.'
'Please do as best you can,' said Inspector Zhang. He stood back and folded his arms.
Mr. Yin sighed, then bent down and retrieved the key. He inserted it into the lock and turned it twice antic- clockwise to open the door. He took out the key, pushed open the door and walked into the apartment.
The three detectives followed him.
'And then you closed the door?'
'Yes. I did.'
'So please do that now.'
Mr. Yin closed the door.
'And where did you leave the boxes?'
Mr. Yin pointed at the side of the sofa. 'There,' he said.
'And then you left the apartment?'
'Yes,' said Mr. Yin. 'Is that all you need from me?'
'Just bear with me a little while longer, Mr. Yin,' said Inspector Zhang. He walked around the sitting room, deep in thought.
'Inspector Zhang, I really think we have imposed on Mr. Yin's public spiritedness quite enough,' said Inspector Kwok. 'He has a business to run.'
'Soon,' said Inspector Zhang. 'We are almost there.'
He walked into the bedroom and Sergeant Lee followed him. 'Inspector Zhang, what are you looking for? We know that the drugs are not in the apartment.'
Inspector Zhang smiled. 'I am not looking for the heroin, Sergeant Lee. I am looking for the boxes, and that is quite a different matter.'
'The boxes?'
'Yes, the boxes. They are key to this.' He smiled. 'If you will forgive the pun.'
'Pun? What pun?' Sergeant Lee frowned in confusion.
Inspector Zhang sighed as he looked around the bedroom. 'The bed was examined, of course. That only leaves the wardrobe.'
'The wardrobe is empty, Inspector Zhang,' said Sergeant Lee. She opened the doors to show him. 'Coat hangers and dust, nothing else.'
'Mr. Yin, come in here please,' called Inspector Zhang.
Mr. Yin walked into the bedroom. He looked annoyed. 'I really must protest,' he said. 'I have a business to run.'
'Would you be so kind as to help me move the wardrobe,' said Inspector Zhang.
'You want me to do what?'
'The wardrobe. Just help me move it.'
'Why?'
'Because I suspect there is something beneath it.' He smiled. 'I can hardly ask the ladies, can I?'
He took hold of the left side of the wardrobe and waited until a reluctant Mr. Yin took hold of the right hand side. They both lifted and moved the wardrobe forward a couple of feet. Sergeant Lee gasped when she saw what had been hidden by the wardrobe. Flattened cardboard boxes. She bent down and picked them up. There were ten of them. 'The boxes,' she said.
'Yes,' said Inspector Zhang. 'The boxes.'
'But how can that be?' asked Inspector Kwok.
Inspector Zhang let go of the wardrobe and looked over at Mr. Yin. 'Why don't you explain, Mr. Yin?'
'I don't know what you mean.'
'Yes you do, Mr. Yin. The drugs were never in the boxes. Not by the time you brought them up to the apartment. They might well have been in the boxes at the warehouse but at some point between there and here you and your assistant took the drugs out and it was empty boxes that you brought into the apartment.'
'Nonsense,' said Mr. Yin.
'There is no other explanation,' said Inspector Zhang. 'You and he were the only people to enter the apartment. It can only have been you.'
'You cannot prove anything,' said Mr. Yin.
'I think I can,' said Inspector Zhang. He pointed at the collapsed boxes. 'When you and your assistant entered the apartment neither of you were wearing gloves. Therefore if you did indeed conceal the boxes under the wardrobe, your fingerprints and DNA will be on the cardboard.'
Mr. Yin glared at Inspector Zhang for several seconds, then his shoulders slumped. 'I have been a fool,' he said.
'I agree,' said Inspector Zhang. 'When you were approached by Inspector Kwok you realised that she was providing you with a golden opportunity to cover your crime. You were the one bringing the drugs into the country, but of course she didn't know that. You put the boxes in the van but on the way to the apartment you removed the heroin and resealed the boxes. The boxes on the trolleys were empty. And once inside the apartment out of sight of the surveillance camera you simply flattened the boxes and hid them under the wardrobe.' He turned to Inspector Kwok. 'You may arrest Mr. Yin now,' he said. 'The mystery is solved.'
Inspector Kwok had been staring at Mr. Yin with her mouth wide open and she jumped when Inspector Zhang spoke. She took out her handcuffs, fastened then to Mr. Yin's wrists, and took him out.
Sergeant Lee was scribbling in her notebook.
'What are you writing, Sergeant Lee?' asked Inspector Zhang.
'Everything,' she said. She looked up from the notebook. 'You knew he was guilty before you even brought him here, didn't you? Before you even found the boxes.'
Inspector Zhang smiled. 'Yes, that's true. I did.'
'How?' asked Sergeant Lee.
Inspector Zhang tapped the side of his head. 'By using ze little grey cells,' he said, in his best Hercule Poirot impersonation.
'Something he said at the warehouse?'
'Before then,' said Inspector Zhang. 'When I watched the surveillance video footage at New Phoenix Park, I knew he was our man.'
'But all we saw was him delivering the boxes and leaving,' said Sergeant Lee. 'Nothing else happened.'
'He unlocked the door,' said Inspector Zhang.
Sergeant Lee's frown deepened.
'It was his first time at the apartment,' said Inspector Zhang. 'But he knew that the key had to be turned twice to open the door. He unlocked the door without any hesitation, but how could he have known that it was a security lock and required two turns of the key?'
'He couldn't,' said Sergeant Lee. 'Unless he had already been to the apartment.'
'Exactly,' said Inspector Zhang. 'You saw the problems that Inspector Kwok had when she tried to unlock the door the first time. But Mr. Yin had no such problems. Because he had already been to the apartment.'
'You solved the case, so why didn't you arrest Mr. Yin? Why did you let Inspector Kwok arrest him?'
'It is her case,' said Inspector Zhang. 'I was only brought in to assist.'
'You have saved her career,' said Sergeant Lee. 'She will take the credit.'
'I solved the mystery, that is all that matters to me,' said Inspector Zhang.
'You are a wonderful detective, Inspector Zhang.'
Inspector Zhang smiled but said nothing.
Later that night, Inspector Zhang's wife served him fish head bee hoon, a creamy vermicelli noodle soup with
