Causal
strong strength
Narrative Connection
How these two moments in the story relate
From
Doctor entrusts Leela with the Great Key
S15E25
·
The Invasion of Time Part 5
To
Doctor and Rodan monitor Sontaran threat
S15E25
·
The Invasion of Time Part 5
Why These Connect
The narrative assertion
"Rodan's successful reactivation of Gallifrey's defense screens (Act 3) directly confirms the repair of the TARDIS's stabilizer circuitry she worked on, closing the invasion point for the Sontaran fleet."
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.