Hey there-! Hope i didn't reply too late,
Alright so, the red haired guy will be caught gambling by the elder brother at chapter 99,, So start from there.
Context before that was : Red haired guy sold away the Archer Shuli gifted him during Christmas and he started behaving suspicious so shuli requested the elder bro and male lead to have a look at him, then it was found out that red hair guy fell into the trap of Shulis brother.. Like it wasn't because of bad friends but because Shuli brother set up a plot to tame red hair, so that they can ruin Shuli family in a way. It was all planned and plotted by a cardinal who was given orders.
Okay so start from 99,,
If the crown price die without receiving any love, Deng I would cry.....