Causal
strong strength
Narrative Connection
How these two moments in the story relate
From
Doctor uncovers Harry’s disappearance from Sickbay
S13E2
·
Terror of the Zygons Part 2
To
Doctor identifies Zygon signal device
S13E2
·
Terror of the Zygons Part 2
Why These Connect
The narrative assertion
"The Doctor's investigation into Harry's disappearance (in Sickbay) directly leads to his discovery of the Zygons' abduction of Harry aboard their spaceship, triggering the revelation of the Skarasen and the Zygons' plan to conquer Earth."
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.