As though emerging from the pool into which we were gazing, the monster darted viciously at us. At once it disappeared: the fish-servant through whose eyes we were seeing all this had evidently retreated from the approach; although, protected by its spines, it could not have been in actual danger.
"How dost thou know of the tunneling?" I asked Aga. "Thy fish-men cannot be present there, in the rear of the tunnel, to report."
"My artisans have knowledge of each forward move," she answered. "I will show thee."
We walked back to the palace and descended to a smooth-lined vault. There we saw a great stone shaft sunk down into the rock of the floor. On this was a delicate vibration recording instrument of some sort, with a needle that quivered rhythmically over several degrees of an arc.
"This tells of each move of the Quabos," said Aga. "It also tells us where they will break through the city wall. How near to us are they, Kilor?" she asked an attendant who was studying the dial, and who had bowed respectfully to Aga and myself as we approached.
"They will break into the city in four rixas at the present rate of advance, Your Majesty."
Four rixas! In a little over sixteen days, as we count time, the city of Zyobor would be delivered into the hands—or, rather, tentacles—of the slimy, starving demons that huddled in the cavern outside!
Somberly we followed Aga back to her apartment.