Causal
strong strength
Narrative Connection
How these two moments in the story relate
From
Doctor uncovers Zygon nerve gas plot
S13E2
·
Terror of the Zygons Part 2
To
Doctor uncovers Skarasen lure mechanism
S13E2
·
Terror of the Zygons Part 2
Why These Connect
The narrative assertion
"Sarah's questioning of the motive behind the nerve gas attack on the Fox Inn prompts the Doctor to examine the signalling device and hypothesize its role in summoning the Skarasen, connecting the mystery of the attacks to the creature's behavior."
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.