Recently I just read chapter 20 of the book Divergent and Tris had a simulation. In the simulation Tris broke the glass which then showed that she is Divergent. After a talk with Four, Tris went to see Tori to ask her about why being Divergent is dangerous. Tori told all she knew then left.
I think it's strange that Four knew that breaking the glass was an act of being Divergent. How could it be? How did Four know? Was he Divergent?