Causal
strong strength
Narrative Connection
How these two moments in the story relate
From
TARDIS Buried Under Collapsing Bridge
S2E4
·
World's End
To
The Doctor and Ian leave for tools
S2E4
·
World's End
Why These Connect
The narrative assertion
"Susan's injury leads to the group splitting up, as the Doctor and Ian go to find tools, while Barbara stays with 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.