Meanwhile , Cui was secretly exchanging letters with Zhu , planning to counteract against the eunuchs .
Zhu also sent Zhu 's key advisor Li Zhen to Chang'an to discuss the matter with Cui .
Meanwhile , Cui was secretly exchanging letters with Zhu , planning to counteract against the eunuchs , and Zhu also sent his key advisor Li Zhen to Chang'an to discuss the matter with Cui .