In 238, when Gongsun Yuan was under attack by Wei's general Sima Yi, Sun Quan, despite his prior rage against Gongsun, correctly judged the situation as one where he might be able to take advantage if Sima Yi were initially unsuccessful, so he did not immediately refuse Gongsun's request for help. However, as Sima Yi was able to conquer Gongsun Yuan quickly, Sun Quan never launched the major attack that he considered if Sima got stuck in a stalemate with Gongsun. That year, he also recognised how Lü Yi, the supervisor of the audit bureau, had been abusing his powers, and had Lü Yi executed; he then further confirmed his trust in the high-level officials by personally writing an emotional letter to Zhuge Jin, Bu Zhi, Zhu Ran, and Lü Dai, blaming himself for the recent problems with his administration while urging them to speak out honestly whenever they saw faults in him.