CHAPTER 16
Efforts to move the big stone apparently officiating as a secret enclosure door had been fruitless, given the impossibility of bringing by the underground river and the narrow corridors heavy equipment that could move or ultimately knocked it over. The ability to destroy it with jackhammers was equally unlikely for the same reasons, so that it only remained as a realistic alternative: clearing the heavy portal separating it from its framework of stone with spikes, hammers and chisels and cleaning the slot of debris. A group of members of the expedition had undertaken this task with perseverance, rotating every couple of hours. It could not be determined previously which was the thickness of the rock and the accumulated debris, but all had expected that the job would last several days.