Unable to find a bench in the too-much-changed park, he seated himself instead on the stone step close to the north entrance. He wanted to read the poem one more time.

Once in the New World, Lou started jogging again, circling the area and looking around.

It was another smoggy morning, and it was not easy for Lou to note that he was being followed.

And for the same reason, it was not easy for the target to discover that he or she was being followed.

Lou was catching up with a middle-aged woman walking in front.

What was Detective Yu going to do?

Under the normal circumstances, Yu would have been able to fall back on Chen, and in some cases, on other colleagues because of Chen. However idiosyncratic Chen appeared to others in the bureau, his opinions carried weight, with a number of major cases to his credit.

So Detective Yu could have said to others in the bureau, ‘That’s the opinion of Chief Inspector Chen.’ And they might have chosen to work together with him.

Not this time, though.

Chen had to remain officially off the case. And Yu’s opinion could hardly have mattered.

But this morning, the seventh morning after the appearance of Xiang’s body near the Wenhui building, could be the very day for Lou to act. The crucial seventh day in the weekly cycle. There was little possibility of Lou’s putting it off to another day.

So it was also the day for Detective Yu to act.

For him, the question was how.

Could he choose to wait until the moment Lou took out the weapon – most likely the hammer – to stop the murderer?

Given the distance between Lou and the target, was Detective Yu capable of preventing the crime in time?

With no help or backup whatsoever, he was not sure that he would be able to arrest Lou single-handedly.

And even if Lou was apprehended there, another lost life could have been added to the casualty list of the serial murderer. ‘I can never forgive myself,’ he vividly recalled Inspector Chen saying with a ghastly pale face after failing to save an innocent victim.

Alternatively, Detective Yu could choose to act preemptively, before another victim was claimed under the smoggy morning sky.

The seven-seven scenario could turn out, however, to be a false one.

To have an innocent man arrested in the open at the New World, Yu knew, would prove to be too much of a public embarrassment to the bureau, particularly at this sensitive juncture, especially under the circumstances of his making the move without having discussed it with the bureau, and as a result his days as a cop would be numbered.

Nevertheless, Yu moved closer behind Lou, who seemed to be doing the same to the middle-aged woman.

It was five forty. Not too much time left according to the time pattern for Lou.

It turned out, however, to be a false alarm, as the woman turned into a small alley in the New World and stepped into the first shikumen house with the black-painted door already open. Perhaps she worked there – a Cantonese restaurant inside the shikumen.