郑庄公派出两位使臣，分别携带着礼物和信件，前往齐僖公和鲁桓公的国度。其中一位使臣归来后，原封不动地将那份礼物和信件带回了来。郑庄公询问此事，那位使臣解释说：“我一到达鲁国，就得知鲁侯被人暗杀后新君即位。我主上的信是写给前任鲁侯的，所以不能交给这位新君。” Zheng Zhuanggong seemed puzzled and asked, “How could the loyal and honest Ru Hou kill someone?” The messenger replied, “I have investigated thoroughly.”

He then recounted how Ru Hou's father, Ru Hui Gong, had died early. A concubine was elevated to become his wife and gave birth to a son named Gongzi Qi. Although Gongzi Qi was older in age than Ru Hou by several years, he held a lower position. According to custom, the throne should have passed to Gongzi Qi.

Ru Hou was a kind-hearted ruler who repeatedly expressed his intention of stepping down once Gongzi Qi came of age. However, after eleven years had passed since his ascension to power, when Gongzi Qi returned from an expedition in Qixian with victories under his belt, he requested the position of Taishi from Ru Hou. Despite this request being denied due to concerns over potential future problems with the succession issue within their own country.

Gong Zi later grew increasingly anxious about these matters and began plotting against Ru Hou out of fear for his own life as well as that of his brother's heir apparent status. He approached Zhong Zuo (Zheng Zhuanggong) saying:

"Mainly because you are always so devoted towards your people; if you were not planning on relinquishing your throne soon enough—then there is no need for any further action."

After some time had passed during which both brothers plotted against one another Zhong Zuo finally agreed upon a plan: During winter festivals when all members of society gather outside city walls for religious ceremonies - while main royal residences are left unattended - they would secretly send an undercover assassin disguised as a servant into such residences at night; killing them without anyone noticing or suspecting anything amiss.

In this manner public opinion would be manipulated making it seem like it was justifiable murder instead; thus protecting themselves from accusations involving regicide while also securing their respective positions within society —and henceforth ensuring peace throughout their lands through calculated strategies used discreetly behind closed doors

Zhuanggong pondered deeply before giving consent saying "The fate of our state will depend on us alone." Thus began a covert operation aimed at eliminating potential threats posed by those seeking power or revenge amongst royalty & nobility in order maintain stability across nations through cunning diplomacy & stealthy actions performed discreetly but effectively