Causal
strong strength
Narrative Connection
How these two moments in the story relate
From
Doctor and Leela welcome K9
S15E8
·
The Invisible Enemy Part 4
To
K9 joins the TARDIS crew
S15E8
·
The Invisible Enemy Part 4
Why These Connect
The narrative assertion
"K9's independent entry into the TARDIS (beat_f181bf56f94271b5) directly precipitates Leela's enthusiastic support for taking K9 (beat_68782e55a1ba6081), removing any choice from the Doctor and formalizing K9's inclusion in the crew."
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.