Causal
strong strength
Narrative Connection
How these two moments in the story relate
From
Polo’s desperate gamble for the oasis
S1E15
·
The Singing Sands
To
Tegana volunteers for the oasis mission
S1E15
·
The Singing Sands
Why These Connect
The narrative assertion
"Diminishing water rations and Marco mentioning the group is exhausted, leads the Doctor to collapse and Barbara being concerned."
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.