Complete Works of Virginia Woolf: The Voyage Out
"Once a monastery," said Mr. Pepper.
She was half-moved to cry, "Stop, William; explain!" and would have returned to the subject at luncheon if William had not shown himself inscrutable and chill, lifting fragments of salad on the point of his fork, with the gesture of a man pronging seaweed, detecting gravel, suspecting germs.
a building in which monks ( = members of a male religious community) live together.
if a person or their expression is inscrutable, it is hard to know what they are thinking or feeling, because they do not show any emotion.