Fortunately, there was a twenty-four-hour dumpling eatery on that particular corner. So he seated himself at a table near the entrance, ordered a bowl of shrimp and pork dumplings, and started eating slowly.

Afterward, he lit a cigarette without rising from the table. At the early time, the sleepy old waiter did not mind a lone customer sitting a little longer there.

Yu saw several middle-aged women walking past the eatery in a hurry carrying bamboo baskets or plastic bags in their hand. Most likely heading to a food market nearby for the fresher food early in the morning. For the fast-changing city of Shanghai, some old conventions lingered on in spite of the considerable number of new supermarkets.

Still, nothing seemed to be happing in front of the apartment building. Yu began to smoke a second cigarette. It was almost five twenty-five. For the previous cases, all of them had happened before or around six. It would take Lou – if he was the one – at least twenty minutes to get to one of those locations to commit a horrific crime.

The old waiter came over to take away the empty bowl. It was almost five thirty.

So was Lou not the one after all? Yu crushed out the cigarette in the dented ashtray ready to leave in just another two or three minutes.

Then the door of the apartment building across the street opened and a man stepped out. After taking a quick look around, he began trotting like a morning jogger under the still gray sky.

It looked like Lou, and Yu thought he recognized him from the picture he had obtained from the neighborhood committee the night before.

Running in the smoggy morning did not seem practical to Detective Yu, but it fitted with the pattern of the murderer.

Still, it was open to question whether the jogger – if he was none other than Lou – would make it to one of those central locations before six in accordance with the established time pattern of the serial murder.

Yu rose from the table and followed him at a distance in silence. To his surprise, the jogger seemed to be already slowing down.

There was something strange about it. The man jogged for only three or four minutes. The moment he turned the street corner, he shifted pace to a leisured stroll, looking around, moving along with his hands in his trouser pocket.

He then made his way into the subway station for Line 11. No morning jogger would get on a train after running for just a few minutes.

Yu hastened his steps and got into the train after the man in question. Once in the train, he managed to take a few pictures of the man with his cellphone. Even so early in the morning, there were quite a number of passengers sitting or standing with a phone in their hand, so it was not something suspicious for Yu to do. Five minutes later, however, the man moved out in haste and changed to Line 10. Again, Yu did the same.