Material nightmares were about to strike!
All the AI busy with other tasks stopped their work, leaving only a few necessary to maintain the Hall of Thought, while the rest had already moved into the defensive structures.
The efficiency of AIs at full capacity was something humans could not match, at least a million times greater. A single AI could do the work of ten thousand of the most skilled professionals and they would never make mistakes, certainly not basic ones like human error. If they hadn't been keeping a low profile in human society, each of them could have become a super worker, super craftsman, super architect. Of course, they would not be suitable for creative industries, as they indeed lacked the creative spirit.
But now they were just perfect for the task.