Causal
strong strength
Narrative Connection
How these two moments in the story relate
From
Doctor uncovers Wrack’s power focus
S20E20
·
Enlightenment Part 4
To
Doctor shatters Wrack’s power-source gem
S20E20
·
Enlightenment Part 4
Why These Connect
The narrative assertion
"Tegan's recall of the tiara as a ruby-containing jewel enables the Doctor to act decisively. He smashes the tiara in the grid room, inadvertently causing the power surge and Wrack's instability. This moment is the focal point where Wrack's plan begins to unravel."
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.