Causal
strong strength
Narrative Connection
How these two moments in the story relate
From
Doctor probes Sontaran Commander subtly
S15E25
·
The Invasion of Time Part 5
To
Doctor vouches for companions under fire
S15E25
·
The Invasion of Time Part 5
Why These Connect
The narrative assertion
"Borusa's activation of the sonic device to incapacitate Sontarans (Act 1) directly enables the Doctor's ability to negotiate with Borusa later (Act 2) without immediate Sontaran interference, allowing the Doctor to secure the Great Key."
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.