With Lin Xiangru and Lian Po working together to defend the state of Zhao, Qin indeed dared not to invade. However, Qin still managed to seize considerable territory from the states of Chu and Wei. At that time, real power in Qin lay in the hands of the Queen Dowager and her brother, Lord Rang (Wei Ran, "Rang" pronounced "ráng"). In 270 BC, Lord Rang planned to send troops to attack the state of Qi.
At this very moment, King Zhaoxiang of Qin received a letter signed by someone named Zhang Lu, requesting an urgent audience.
Zhang Lu was originally from the state of Wei and his real name was Fan Ju (pronounced "jū," also read as "suī"). He had once been a retainer of Xu Jia (pronounced "gǔ"), a high official of Wei. On one occasion, Xu Jia took Fan Ju with him on a diplomatic mission to Qi. King Xiang of Qi, hearing that Fan Ju was talented, secretly sent someone to meet him and presented him with a generous gift. Fan Ju firmly declined it.
Because of this incident, Xu Jia suspected Fan Ju of secretly colluding with Qi. After returning to Wei, he reported Fan Ju to the Chancellor Wei Qi. Wei Qi subjected Fan Ju to severe torture, beating him nearly to death, breaking his ribs, and knocking out two of his front teeth. Finally, Wei Qi ordered men to wrap Fan Ju in a ragged mat and throw him into a latrine.
When night fell, Fan Ju slowly regained consciousness and saw a guard watching over him. He pleaded for help. The guard secretly helped Fan Ju escape but reported back to Wei Qi that Fan Ju had died.
Fearing pursuit by Wei Qi, Fan Ju changed his name and surname, calling himself Zhang Lu.
At that time, Qin happened to have an envoy traveling to Wei. Fan Ju secretly approached the envoy, who then brought him to Qin.
After arriving in Qin, Fan Ju submitted a memorial to King Zhaoxiang of Qin. The king set a date and agreed to meet him at a detached palace.
On the appointed day, as Fan Ju was walking to the detached palace, he encountered King Zhaoxiang of Qin arriving in his carriage. Fan Ju deliberately pretended not to recognize the king and did not move aside.
The king's attendants shouted loudly: "The king is coming!"
Fan Ju coldly replied: "What? Does Qin even have a king?"
As they argued, King Zhaoxiang arrived and overheard Fan Ju still muttering: "I've only heard of the Queen Dowager and Lord Rang in Qin—where is there any king?"
These words struck a chord in the king's heart. He immediately invited Fan Ju to the detached palace, ordered everyone else to withdraw, and received Fan Ju in private.
King Zhaoxiang said: "I sincerely ask you to instruct me. No matter who is involved—up to the Queen Dowager, down to all the officials—you may speak freely and directly."
Fan Ju began his discourse. He said: "Qin possesses vast territory and brave soldiers. To dominate the feudal lords should be an easy task. Yet for the past fifteen years, there has been little accomplishment. This cannot be blamed solely on the Chancellor (referring to Lord Rang) failing to serve Qin loyally, but also on Your Majesty's own strategic errors."
King Zhaoxiang asked: "Where do you think I have erred?"
Fan Ju replied: "Qi is far from Qin, with the states of Han and Wei lying in between. If Your Majesty sends troops to attack Qi, even if you defeat Qi smoothly, you would have no way to connect Qi's territory with Qin's. In my opinion, the best strategy for Your Majesty is to 'befriend the distant and attack the nearby.' Temporarily stabilize relations with distant Qi, while first conquering the neighboring states. This will expand Qin's territory. Every inch gained is an inch secured, every foot gained is a foot secured. Once the states of Han and Wei are annexed, Qi will inevitably fall."
King Zhaoxiang nodded in agreement and said: "If Qin is truly to conquer the six states and unify the Central Plains, it will be entirely thanks to your strategy of 'befriending the distant and attacking the nearby.'"
Immediately, King Zhaoxiang appointed Fan Ju as a guest minister and, following his strategy, targeted the states of Han and Wei as the primary objectives for attack.
A few years later, King Zhaoxiang dismissed Lord Rang from his position as Chancellor and prevented the Queen Dowager from interfering in government affairs, formally appointing Fan Ju as Chancellor.
The King of Wei, under severe threat from Qin, was extremely alarmed. Chancellor Wei Qi, learning that Qin's Chancellor was a native of Wei, sent Xu Jia to Qin to seek peace.
When Fan Ju heard that Xu Jia had arrived in Qin, he changed into shabby clothes and went to visit him at the guesthouse.
When Xu Jia saw Fan Ju was still alive, he was greatly startled and asked: "What are you doing now?"
Fan Ju replied: "I'm just serving as a menial here."
Seeing Fan Ju poorly dressed and shivering from the cold, Xu Jia took off a fine silk robe and gave it to him, then invited him to stay for a meal.
Xu Jia said: "I've heard that the King of Qin greatly trusts Chancellor Zhang Lu. I'd very much like to meet him. Do you know anyone who could introduce me?"
Fan Ju said: "My master happens to know the Chancellor. If you wish to meet him, I'll attend you and take you there."
Fan Ju accompanied Xu Jia to the entrance of the Chancellor's residence and said: "Please wait a moment; I'll go announce your arrival."
Soon after Fan Ju went in, a command came out: "The Chancellor is receiving guests—call Xu Jia in." Xu Jia asked the gatekeeper: "The man Fan Shu who came with me just now—why hasn't he come out?"
The gatekeeper replied: "What Fan Shu? The man who just went in is our Chancellor himself!"
Only then did Xu Jia realize that Chancellor Zhang Lu was actually Fan Ju. He broke out in a cold sweat. Upon entering, he fell to his knees, crawled to Fan Ju, and kowtowed repeatedly, saying: "I, Xu Jia, was blind and offended the Chancellor. Please punish me!"
Fan Ju harshly rebuked Xu Jia, then said: "Today, you saw me and gave me this silk robe—this shows you still have some humanity. For this reason, I will spare your life." Then, he instructed Xu Jia to carry a message to the King of Wei: Wei Qi must be executed before Qin would allow Wei to cede territory and make peace.
Xu Jia returned to Wei and relayed Fan Ju's message to the king. The King of Wei willingly agreed to cede land for peace. With no way out, Wei Qi committed suicide.
After Wei sought peace, Qin followed Fan Ju's strategy of "befriending the distant and attacking the nearby," launching its first major offensive against the state of Han.