"In this regard, I can provide you with some clues. The virus originally came from a foreign pharmaceutical research institution. This institution has very, very little cooperation with our domestic counterparts. If you collect some information, then you should be able to figure out their partners."
"Even if we find the partners, what does that prove? Could we really show that the partners brought in this virus from them back then? I don't think it's necessarily the case."
"You're wrong. The way this institution chooses its partners is very, very special. Under normal circumstances, they absolutely wouldn't collaborate with just anyone. So in this case, you can only be in a long-term and very stable partnership with them before there's a chance they'll provide you with this virus."