No matter how hard the golems hit the wall of Sun’s cell, they are not doing significant damage to it: their hit will make a crack, but it will be magically repaired instantly.
“What is happening P’Khan? Why is my room shaking?” asked Sun.
“We are trying to break down the wall. Get back as far as you can, Master Sun.”
When Khan sees that they are not progressing at all, he tells the golems to stop. As he thinks of another way to get Sun out, an alarm sounds throughout the Prison Room.
“Oh no,” said Khan. His vambrace, then, shines and he reads the message it shows.
“You’ve been discovered, sir. Get out of there – and fast. Lady Nemesis has disabled all kinds of Transport Magic inside the Prison Room, and Lord Thanatos has called for me probably to stop you. GET OUT NOW!” The warning is from Janzo.