Causal
strong strength
Narrative Connection
How these two moments in the story relate
From
Ian rescues Arbitan from Voord attack
S1E21
·
The Sea of Death
To
TARDIS locked by Arbitan’s blackmail
S1E21
·
The Sea of Death
Why These Connect
The narrative assertion
"Arbitan says he will release Ian's companions; they return to the TARDIS on the island."
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.