The ninth prince bring's the Empress's twin nieces as concubines for Feng garbage, the prince and Yu Heng scam 5 million gold teals out of the princess, something happens where garbage man consummates with the twins, one that night and the other the next night, preventing him from doing it with Kang Yi. Kang Yi goes out that night and meets the third prince, Yu Heng follows, gets confirmation that they are conspiring and is super pissed. I kinda skipped around the novel, so I'm not sure what happens after that.