Causal
strong strength
Narrative Connection
How these two moments in the story relate
From
Doctor quietly defies Polo’s order
S1E16
·
Five Hundred Eyes
To
Doctor learns cave location from spy
S1E16
·
Five Hundred Eyes
Why These Connect
The narrative assertion
"Because of Barbara's disappearance, Susan and Ping-Cho reveal their theory to the Doctor that she went to the Cave of Five Hundred Eyes."
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.