But the boy was trying to fight off the dementors, even though Harry could see their cold, draining power starting to affect him. The crowd was jeering, some of them on their feet, as the woman swept out of the dungeon, and the boy continued to struggle.
“I'm your son!” he screamed up at Crouch. “I'm your son!”
“You are no son of mine!” bellowed Mr. Crouch, his eyes bulging suddenly. “I have no son!”
The wispy witch beside him gave a great gasp and slumped in her seat. She had fainted. Crouch appeared not to have noticed.
“Take them away!” Crouch roared at the dementors, spit flying from his mouth. “Take them away, and may they rot there!”
What does "may they rot there" mean? Is it let them rot in the prison Azkaban?
-- From Harry Potter and the Goblet of Fire