Lu Chen eventually accepted Qin Yushan's suggestion and directly wrote a family letter to the Sum Emperor.
First, he complained in the letter about how terribly harsh the environment in North City was, and then he pretended to ask for aid, hoping the Sum Emperor could dispatch a large army as soon as possible to help him resist the Barbarian Tribe.
It was near the end of the letter that Lu Chen mentioned his recent discovery of many iron tools unique to Great Sum on the grasslands.
Lastly, he affected a very aggrieved demeanor in the letter to complain about how Prince Lu Shuyun's trading caravans often appeared in North City, and, flaunting Prince Lu Shuyun's backing, frequently avoided paying the transit tax. He hoped the Sum Emperor would punish Prince Lu Shuyun, tone down his arrogance and, ideally, make him pay all the transit taxes his caravans owed.