Causal
strong strength
Narrative Connection
How these two moments in the story relate
From
Barbara detains Susan after class
S1E1
·
An Unearthly Child
To
Barbara convinces Ian to investigate
S1E1
·
An Unearthly Child
Why These Connect
The narrative assertion
"The school bell rings, and Barbara asks Susan to wait for her, leading to Barbara expressing her concern about Susan Foreman to Ian."
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.