Causal
strong strength
Narrative Connection
How these two moments in the story relate
From
Trapped trio weighs desperate hope against fate
S15E20
·
Underworld Part 4
To
K9 blasts companions free from rockfall
S15E20
·
Underworld Part 4
Why These Connect
The narrative assertion
"The rockfall trapping the Doctor, Leela, and Idas is undone by K9 blasting through it at the last moment, freeing them just as the R1C's launch countdown nears completion."
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.