"The apartment was just like this when you entered?" he asked.
"Exactly," said Inspector Kwok.
Inspector Zhang knelt down carefully and peered under the bed. Another cockroach scuttled away and disappeared under the skirting board.
"We looked everywhere," said Inspector Kwok.
"I'm sure you did," said Inspector Zhang.
"But as you can see, it is a small apartment and there are no hiding places."
Inspector Zhang tapped the floor with his foot.. The bedroom floor was tiled, as was the sitting room, bathroom and kitchen. It was the same pale green tiles in all the rooms.
"How long were the men in the apartment?" he asked.
"Two minutes. Three at most. They left the boxes and then they took the trolleys back to the van."
Inspector Zhang nodded thoughtfully. He looked up at the ceiling. It was plaster, painted white.
He went over to the bedroom window and opened it. He peered out. Down below was a car park. There were no ledges or balconies, and no external pipework that would have allowed someone to have climbed out.
"We had a car down there with two undercover police officers," said Inspector Kwok. "They had the rear of the building under constant surveillance."
Inspector Zhang craned his neck to look upwards.
"If anyone had lowered the drugs up or down through the window, we would have seen it," Inspector Kwok said.
"One would hope so," said Inspector Zhang.
He pulled his head back in and looked over at Sergeant Lee., who was standing at the bedroom door, taking notes. "What do you think, Sergeant?"
Sergeant Lee looked up from her notebook. "It is a mystery, Inspector Zhang," she said.
"Indeed it is. Do you have any thoughts on how we might solve it?"
She frowned thoughtfully. "The drugs were brought into the apartment and they are clearly not here now," she said. "They must therefore have been removed. The question is how were they removed? If they were not lowered out through the bedroom window, then perhaps through the sitting room. There is a balcony there."
Inspector Zhang went through to the sitting room and opened the sliding glass door that led to a small balcony where there was an air-conditioning unit and three large ceramic plant pots which were filled with soil and the remains of long-dead flowers.
"We had the front of the building under observation, obviously," said Inspector Kwok. "During the time we had the building under surveillance no one appeared on the balcony."
Inspector Zhang examined the plant pots. They were each over two feet high with paintings of feeding cranes and bamboo on the side. They were of poor quality and the glaze was cracking.
Inspector Zhang tipped one of the plant pots on its side, then up-ended it and with a grunt lifted it up. Soil spilled out over the balcony.
He did the same with the other two plant pots. They both contained nothing but soil. Inspector Zhang stared down at the dirt thoughtfully. "So, the drugs are not on the balcony and they did not leave by the windows." he said quietly. "There are therefore only two possibilities. Either they are still in the apartment but so well hidden that we cannot see them, or they were removed by some other route."
"But how is that possible?" asked Inspector Kwok. "We have searched everywhere."
Inspector Zhang walked through to the kitchen. There was a broom leaning behind the door and he picked it up. He turned it upside down and methodically tapped the handle against each of the tiles on the floor. They all made a dull thudding sound as he hit them. He did the same in the shower room, and then repeated the process in the sitting room and the bedroom. Every tile sounded the same.
"Inspector Zhang, we checked the floor," said Inspector Kwok. "And the ceiling. Both are completely solid."
"I'm sure you did," said Inspector Zhang. "But there is no harm in my checking for myself."
He walked around the apartment, tapping the ceiling at regular intervals. He checked the kitchen, the shower room, the sitting room and the bedroom. There was no difference in sound anywhere, no indication that there were any trapdoors or hidden compartments. The ceiling was as solid as the floor.
Inspector Zhang gave the broom to Sergeant Lee and she returned it to the kitchen.
"Did you speak to the occupants of the apartments on either side of this one?" Inspector Zhang asked Inspector Kwok.
"Of course. There is an old couple to the left. He is a retired schoolteacher and his wife is bed-ridden. Their bedroom is next to the kitchen and bathroom of this apartment. To the right is a young Indian girl with two young children. Her husband is a construction worker in Dubai. She only leaves the house to go shopping or to occasionally take the children to the park. We checked her side of the party wall and there is no way anyone could have gotten through."
Inspector Zhang stood in the middle of the sitting room, looking around. "So, we are sure that the drugs did not pass through the walls, or through the floor or the ceiling, or go out of the windows."
"That is correct, Inspector Zhang."
"And you saw the ten boxes being brought in? Each box would be how big, exactly?"
Inspector Kwok used her hands to demonstrate the size of the box. About fifty centimetres wide, twenty-five centimetres long, a foot wide, and twenty-five centimetres tall.
Inspector Zhang rubbed his chin. "And you have checked the sofa and the television?"
"Of course." She moved the sofa so that he could see a long cut that had been made in the material at the back. "We took the television apart and the refrigerator. And the shower cubicle. And the bed. There is nowhere in the apartment where a hundred kilos of heroin could be hidden."
Sergeant Lee came out of the kitchen. "What about the drains, Inspector Zhang?" she asked.
"The drains?" said Inspector Zhang, frowning.
"What if they unpacked the drugs and somehow dropped them down the drain? In the shower room or the kitchen."
"Throw them away, you mean?"
"No, Inspector, I meant they could have wrapped the drugs in something waterproof and then sent it down the pipes to an accomplice down below. The accomplice could have intercepted the drugs before they reached the sewage system."
Inspector Zhang. Nodded approvingly. "Why, Sergeant, I had no idea that you were so resourceful. What an intriguing idea."
"Do you think it's possible?"
"Sadly, no," said Inspector Zhang. "The heroin was packed in one kilo packages, and they would not fit down the pipes in either the kitchen or the bathroom. Someone would have had to have repackaged all the heroin which would have taken hours and we know that there was no one else in the apartment." He looked across at Inspector Kwok. "Is that not the case?" he asked.
"There was no one inside, we are sure of that," said Inspector Kwok.
"But can you be sure?" asked Sergeant Lee. "Your men did not enter the apartment with the delivery men. There could have been someone hiding in the bedroom. They could have waited until the delivery men left and then repackaged the drugs and flushed them down the waste pipes to be collected by an accomplice downstairs."
Inspector Kwok's lips tightened in annoyance. "We had the apartment under constant surveillance and no one left the premises. There was no one there when we entered. Therefore we are certain that the apartment was empty all the time we had it under surveillance."
"What about the recording of the CCTV footage?" asked Inspector Zhang. "Where is that?"
"We have taken it to New Phoenix Park," said Inspector Kwok. "We wanted our technicians to check that there was nothing wrong."
"What did you think might be wrong?"
Inspector Kwok shrugged. "The Senior Assistant Commissioner thought that perhaps the camera had been interfered with. That perhaps someone had blocked the camera somehow while they removed the drugs."