Causal
medium strength
Narrative Connection
How these two moments in the story relate
From
Core breakthrough plans take shape
S15E18
·
Underworld Part 2
To
Doctor sacrifices himself to save Idas
S15E18
·
Underworld Part 2
Why These Connect
The narrative assertion
"Leela's concern about energy (beat_a8e7e18154631164) echoes the Doctor's later prioritization of others' safety over his own (beat_9ecaeb123cae0e76), as both moments highlight ingenuity and self-sacrifice for survival and liberation."
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.