Causal
strong strength
Narrative Connection
How these two moments in the story relate
From
Tyler swallowed by antimatter entity
S10E1
·
The Three Doctors Part 1
To
Doctor and Jo depart for crime scene
S10E1
·
The Three Doctors Part 1
Why These Connect
The narrative assertion
"Doctor Tyler's vanishing after developing the X-ray plate provides the key visual evidence (the contorted face on the plate) that compels the Doctor to become involved in the investigation, leading to Tyler and Jo departing for the scene of the crime."
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.