Narrative Connection
How these two moments in the story relate
Why These Connect
The narrative assertion
"Marco Polo's act of returning the TARDIS in Episode 20 sets up the companions' arrival in Millenius in Episode 26, where they encounter Altos and Sabetha under Yartek's control."
inferred by llm_cross_episode_arc
Why This Matters Across Episodes
The longer arc this connection carries
The TARDIS's presence (via its return) enables the companions to re-enter the narrative of Marinus, directly leading to their interactions with Altos and Sabetha. Without the TARDIS's return, the companions wouldn't be in Millenius to confront Yartek.
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.