"Thrice he?d escaped from prison, and but for the recent wave of unrest in the maximum-security establishments
up north, he wouldn?t now be gracing the Governor?s premises in Oxford; and the Governor was going to make absolutely certain that he wouldn?t be disgracing them."

Explain the above lines.

Dear student,

These lines describe how Evans had been successful in escaping from prison thrice. Due to this, he would have been imprisoned in the extremely secure prison up north, but there was some unrest there which prevented his imprisonment in that safe establishment. To ensure that he was kept in a secure area to curtail his escape attempts, he was going to be kept in the Governor's premises(building). The Governor would then make sure that Evans would not insult them by escaping again.

Regards