Causal
strong strength
Narrative Connection
How these two moments in the story relate
From
The Doctor entrusts Ian with the key
S1E26
·
The Keys of Marinus
To
Yartek’s Key Demand and Ian’s Deception
S1E26
·
The Keys of Marinus
Why These Connect
The narrative assertion
"The Doctor entrusting the key to Ian leads directly to Ian and Susan's encounter with Yartek who is disguised as Arbitan, driving Yartek to demand the key from Ian and Susan."
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.