Jaime feels the guilt of his fathers death. He hasn‘t seen Varys since helping Tyrion escape. When he went to question the undergaolers they were all killed by the Kingsguard at Cersei‘s behest.
Cersei comes to see him in The Great Sept & She pleads with him to be Hand & they can rule like King &Queen. He declines.
Still upset with her, but he gives Cersei advice on handling Mace Tyrell, but it means rushing Margaery &Tommens wedding