4I

What did you think the severest vengeance could be, or could mean, that the Knight thought had arrived?

The judgement of God and the loss of dignities and honors and deprived of the Sacrament of Holy Communion.

I agree with >2 JohnDBurke:

Something appropriately melodramatic.

I assumed there was an ambush lined up and they were all going to be killed in the Cathedral or when they left it.

>2 JohnDBurke: Easily the answer, or the Knight's own personal pursuit of vengeance.

Same as >2 JohnDBurke:. God’s judgement..

I assumed the severest vengeance to be death. I expected the Knight (wish Berry would just give the man a name!) was waiting for Cotton et al to find ‘whatever-it-is’ with the intention of killing them to get it.