Narrative Connection
How these two moments in the story relate
Why These Connect
The narrative assertion
"Susan's suspicion of Tegana in Episode 15, later echoed by Barbara's warnings in Episode 16, creates the investigative mindset that leads the Doctor to forge a duplicate TARDIS key."
inferred by llm_cross_episode_character
Why This Matters Across Episodes
The longer arc this connection carries
Susan and Barbara's growing distrust of Tegana in Episode 15 primes the group to uncover risks, which culminates in the Doctor's resourceful decision to forge a key in Episode 16—a direct response to Tegana's and Polo's threats.
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.