Causal
strong strength
Narrative Connection
How these two moments in the story relate
From
Doctor’s Wounded Return and Split Mission
S4E22
·
The Underwater Menace Part 4
To
Tunnel Collapse Under Rising Tide
S4E22
·
The Underwater Menace Part 4
Why These Connect
The narrative assertion
"The Doctor reveals his plan to flood the lower levels of Atlantis, which directly creates unstable conditions that Polly notices as a glowing wall seems to be crumbling, and Polly attributes the wall's instability to vibrations within the tunnel."
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.