Causal
strong strength
Narrative Connection
How these two moments in the story relate
From
Mara takes full possession of Tegan here
S20E5
·
Snakedance Part 1
To
Doctor warns of Mara in Chamber
S20E5
·
Snakedance Part 1
Why These Connect
The narrative assertion
"Lon's agreement to meet Tegan based on the Doctor's scientific explanation of the Mara's mental force directly leads to the tense moment where the Doctor tries to take Lon to her, but Tegan is triggered and flees—ultimately sealing her possession."
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.