Causal
strong strength
Narrative Connection
How these two moments in the story relate
From
Doctor learns Romana abducted
S18E11
·
Full Circle Part 3
To
Science team discovers Mistfall trace in alien tissue
S18E11
·
Full Circle Part 3
Why These Connect
The narrative assertion
"Login’s introduction of the concept of Mistfall during the Doctor’s dissection of the dead spider enables the Doctor to make a breakthrough about the nitrogen cycle and ecosystem integration—directly advancing the investigation into the planet and creatures."
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.