Causal
medium strength
Narrative Connection
How these two moments in the story relate
From
Brigadier’s Failed TARDIS Key Attempt
S7E2
·
Spearhead from Space Part 2
To
Doctor Proves Identity Through Memory
S7E2
·
Spearhead from Space Part 2
Why These Connect
The narrative assertion
"The Brigadier's inability to open the TARDIS with the key emphasizes the Doctor's unique connection to it, making him more believable when he arrives at UNIT HQ and claims to be the Doctor."
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.