Evidently he had received a shocking impression of the state of affairs in the island; that is the only explanation of the action suddenly taken by him, for his first public act was to demand from James the release of all the prisoners in the fortress, in order that they and their accusers should appear before him.
James is in a difficulty; and, mule-like, since he does not know which way to turn, stands stock still.

He can do nothing, he says, without the Admiral's consent.

The next day Bobadilla, again hearing mass in state, causes further documents to be read showing that a still greater degree of power had been entrusted to his hands.

Mule-like, James still stands stock still; the greatest power on earth known to him is his eldest brother, and he will not, positively dare not, be moved by anything less than that.

He refuses to give up the prisoners on any grounds whatsoever, and Bobadilla has to take the fortress by assault--an easy enough matter since the resistance is but formal.
The next act of Bobadilla's is not quite so easy to understand.