Characters
What makes you think she's a witch?
— Bedevere · Monty Python and the Holy Grail

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The speaker challenges an accusation, asking what reason there is for believing someone is a witch. The question puts the burden of proof on the accuser and hints at doubt about the claim, inviting evidence rather than accepting the label at face value.
Context reviewed