User blog comment:WhiteSeraph/Alternate Timeline Idea That I'm Really Psyched About/@comment-3341288-20110929013202/@comment-3341288-20110929020450

I say the TS find out that Horus's illness is chaos related. Then Big E. informs his primarchs of the truth of Chaos. Explains why he kept it quite and teaches then to guard against it. Plus letting them know VERY SPECIFICALLY that using Chaos is a all around bad idea.