Causal
strong strength
Narrative Connection
How these two moments in the story relate
From
Doctor and Nyssa test the Great Crystal
S20E6
·
Snakedance Part 2
To
Crystal resonates with Mara's return
S20E6
·
Snakedance Part 2
Why These Connect
The narrative assertion
"The Doctor’s experiment in the TARDIS—focusing thought on the crystal—directly results in the crystal glowing in synchronization with Tegan’s activation of the secret door in the Chamber of the Mara, proving the interconnectedness of mind, artifact, and reality."
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.