Still in shock after Rick’s departure? I know I am. Why not look further into depth within my official review of Episode 5. Here’s some foreshadowing I missed beforehand. Watching the episode, do you remember seeing Sasha rise from the dead? The scene Rick hallucinated was filled with alive as well as confirmed deceased characters and one particular character (Sasha) stood up, speaking to him once more.
In the shot below we see Sasha still struggling after her brother Tyreese departed the show, after two powerful seasons. Sasha lays with the dead because she feels a connection to them, just like many other characters do (Michonne) for example. Sasha becomes addicted to killing the dead, on a very destructive path that would only lead to certain death until she became best friends (And lover) to Abraham Ford.