DOCTOR: Astra, we need you to help us to find the Shadow. SHADOW: To the Doctor. Stop! The Black Guardian, he who walks in darkness, and you are in the valley of the Shadow. [SCENE_BREAK]
DRAX: It's working. [SCENE_BREAK]
SHADOW: The Key to Time, Doctor.
Plan: A: Drax's help; Q: Who helped the Doctor escape from their prison? A: The Shadow; Q: Who uses Astra to further the Black Guardians plot? A: The Shadows plan; Q: What is the Doctor trying to stop? A: Time; Q: The Key to what does The Shadow want? Summary: The Doctor with Drax's help, escape from their prison and work to stop The Shadows plan. The Shadow uses Astra to further the Black Guardians plot to obtain the Key to Time.