Foreshadowing
strong strength
Narrative Connection
How these two moments in the story relate
From
Colonel neutralizes Chorley and approves explosive plan
S5E25
·
The Web of Fear Part 3
To
Missing sphere triggers Yeti sabotage
S5E25
·
The Web of Fear Part 3
Why These Connect
The narrative assertion
"The plan to blow up the tunnel is directly threatened by unknown source which gives reason to believe the there is a traitor."
About Foreshadowing Connections
A hints at B. The first event plants narrative seeds that pay off later. These connections reward attentive viewers with a sense of inevitability on rewatch.