Absinthe said:
Okay Nevill, what facts am I discarding?
Major ones.
First, the killer implicated the constables without knowing that chief Zheng will conveniently return to stay there with the bloodied sword over the corpse when the guards arrive. If Fu Xia did it, then he cast suspicion on himself without an alibi and without a prior knowledge that there would be a better suspect.
Second, the killer knows Xueguzi technique, and they are very secretive and seclusive people. If we think the idea of chief Zheng being an assassin that secretly knows such a tech is ridiculous, then we might as well extend this line of reasoning to Fu Xia.
Third, he was acting in a way that attracts way too much attention to the point we all agreed to watch him closely. If he is some kind of a super-agent, and not a one-time hire, attracting attention of that sort is something you absolutely would not do.
Fourth, if we want to, we can guard Xiaofang until the consciousness returns to him. At that point, he can point to Fu Xia. So why all this bluff? He should have fled the moment we discovered Xiaofang and he realised his plan failed -
if this was his plan. But he is still here.
That, coupled with you blowing several other, much more minor facts out of proportions is why I don't bother with disproving your theory. It is founded on a few suspicions and a lot of paranoia.
For the record, I don't think Fu Xia is a murderer. He can be a mole, a distraction, an idiot - this would be consistent with his behavior so far - but it is not consistent with him being an assassin. And if he is not one, then trying to force him to confess his crimes is not going to do much to prove chief Zheng's innocence or to spare him, which is my main goal.
The only real argument you have against him is that Xiaofang knew the assailant, and that could have been another one of the eunuchs for all we know.
Absinthe said:
Also, it's possible that Fu Xia (as the mole&killer) doesn't have fellow agents at Youxia City. Heck, this is likely considering we found Xiaofang; if there's another killer up to this in Youxia City, they would've had enough time to dispose of Xiaofang thoroughly.
That would point to Fu Xia working alone. If he wasn't, his employer would have learned about this expedition from him and send the assassins there. In fact,
whoever massacred the constables lead us here, so there is plenty of reasons to assume that if they had people to spare, this is the place where they would station them.
But if this isn't the case, then Fu Xia is a one-man faction, and that means he was the one behind the attack on the constables. So he must have the manual. Q.E.D.