Causal
strong strength
Narrative Connection
How these two moments in the story relate
From
Bert relinquishes hope and Jo agrees to escape
S10E22
·
The Green Death Part 2
To
Doctor spots ominous green light
S10E22
·
The Green Death Part 2
Why These Connect
The narrative assertion
"Bert’s worsening condition from the green substance at the west seam (seen in Bert’s glowing fingers) directly leads to the Doctor’s solo pursuit, as the speed of infection demands immediate rescue despite extreme danger."
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.