A look into Grisha's memories shows Eren the many secrets his father was hiding, including one which led to his mother's demise.
Thus began the Dark Ages...
...وهكذا بدأ عصر الظّلمات
Es begann eine Zeit der Finsternis.
Entonces empezó la Época Oscura.
Entonces empezó la Época Oscura.
С тех пор наступили тёмные времена.