What are some excellent examples of a series foreshadowing a later event?

I hope this fits. The end of Rome Season 1. Attia and Octavian are standing before Servillia as she gloats about the death of Caesar. How all of Caesar's works are at an end. It's all due to her and Attia better damn well get on her knees and know she will keep her wishing she was dead. Servilia then smugly dismisses Attia and Octavian...but Octavian gives a look of calculated, depthless rage, in a glance then walks away. Now perhaps for many they think ah he may become something. For those who know what Octavian, or Agustus becomes. One of the most powerful political entity in all of human history. I shivered knowing 'you are in for it Servillia'.

/r/television Thread