Da Tiechui memories continue to 10 years ago when the Qin attacked the Yan with 300,000 troops Commanded by General Wang Jian. With only 50,000 troops for defence, General Da Tiechui was commanded by Yan Yi to defend the Mountain Valley border with only a small troop. As Da Tiechui's troops were about to be completely over-run, Yan Yi refused to send reinforcements dooming them to defeat while he offered to trade the Prince's life to save his own. (thetvdb.com)