Causal
strong strength
Narrative Connection
How these two moments in the story relate
From
Chen’s Betrayal and Dalek Extermination Order
S3E21
·
Destruction of Time
To
Doctor sacrifices safety to save companions
S3E21
·
Destruction of Time
Why These Connect
The narrative assertion
"The Daleks' pursuit of Chen after his threats leaves Steven and Sara unguarded, allowing the Doctor to emerge and seize the opportunity."
About Causal Connections
A directly causes B. The first event sets forces in motion that produce the second. These are the load-bearing connections of plot--remove one and the story structure collapses.