《Crypto Power Struggles》Chapter 2:

Although ETH was locked in a dungeon, assassins still secretly passed messages. On a dark, windy night, Prince BCH slipped into the dungeon for a clandestine meeting with ETH, and the two reached an agreement to join forces against SOL.
ETH instructed BCH to unite with the remnants of the prince’s faction in court and spread rumors, saying that SOL intended to stage a rebellion. SOL had already received the word and secretly arranged a counter-move to turn the tables.
When Old Emperor BTC saw that SOL had uncovered the plot so quickly, he became even more wary of him (it can be viewed as the prince and the chancellor secretly colluding against the general; although the general saw through it, it ironically made the old emperor even more suspicious of him).