The Price of Love

Hello, author. I just finished playing your map. The scenario was really good! It was interesting and not monotonous. I was playing on the easiest difficulty level, as I just started playing Heroes. I just didn't understand the ending: first, I chose to "spare the traitor," and on the way home, I was defeated by the Archangel. I replayed, and after the battle, the game simply told me that my heroes were dead and it was game over... What did I do wrong?