‘Unless with some unpredictable factors, one day more or less, for the cycle of seven.’

‘Friday or Saturday, there’s not much time left for us,’ Yu repeated himself, wringing his hands.

‘Now the rationale of the seven-seven is about some special offering to the deceased. My mother used to go to the food market so early in the morning, I remember, for a special meal – at least with fish and meat, and father’s favorite Yunnan ham too – on the seventh day for seven weeks. And that along with the nether world money, the incense, the candles and what not. In short, some really special offering for the deceased.’

‘In other words, the murderer simply takes other lives as special ritualistic offerings to the deceased. Certainly way more special than an exceptional meal. So he will at least take three more lives – to the end of the seven-seven – before coming to a stop. What can we do?’

‘That being the case,’ Chen said, refilling his mug, ‘we may start checking for somebody who died – quite possibly unfair, as seen in the murderer’s mind – seven days before the appearance of Peng’s body near the Bund. That may be a long shot, but worth trying.’

‘But it’s not an easy job for such a large city. More than hundreds of people die on a single day.’

‘We can try to narrow it down,’ Chen said, with a sudden edge in his voice. ‘Let’s start with hospitals.’

‘There’re a number of hospitals, too.’

‘It’s possible to narrow it down further. For the present case, as we have discussed, we have reasons to assume the murderer is a young or middle-aged man, capable of killing with speed and force, knowledgeable about how to stay out of the way of the patrolling cops and the surveillance cameras; and the dead, a woman closely related to him, about the same age. That’s what pushed him over the edge.’

‘Anything else for the profile?’

‘In his mind, the tragedy should not have happened. Medical malpractice, for instance. Considering the first victim was from a hospital too, we may look into that very hospital.’

‘It’s so logical, Chief. Medical disputes make so many headlines online and off in today’s society. In the light of it, the first victim being one from the hospital also makes sense. It’s brilliant, that deduction of yours, Inspector Chen.’

‘No, it’s you that have drawn my attention to it. The yellowish mask from the hospital, though it may be something different from a medical dispute.’

‘I’ll be damned, Chief. I have to go to the hospital right now.’

‘Yes, I have to leave too,’ Chen said. ‘For a good meal with an old friend.’

Staring at his boss, Yu said instead, ‘Come on, Chief Inspector Chen. You are sounding more and more like an impossible gourmet.’

As Detective Yu was leaving the café, Inspector Chen glanced at his watch. Quite a while had elapsed since the ending of the preview. With nothing suspicious detected at the club entrance, he saw no point staying any longer at the café.