When they came to the surface again, they remained for a few minutes
extended on their backs, inhaling the air delightfully. Arcades, one
behind another, opened up amid large walls separating the various
basins. All were filled, and the water stretched in a single sheet
throughout the length of the cisterns. Through the air-holes in the
cupolas on the ceiling there fell a pale brightness which spread upon
the waves discs, as it were, of light, while the darkness round about
thickened towards the walls and threw them back to an indefinite
distance. The slightest sound made a great echo.

Spendius and Matho commenced to swim again, and passing through the
opening of the arches, traversed several chambers in succession. Two
other rows of smaller basins extended in a parallel direction on each
side. They lost themselves; they turned, and came back again. At last
something offered a resistance to their heels. It was the pavement of
the gallery that ran along the cisterns.

Then, advancing with great precautions, they felt along the wall to
find an outlet. But their feet slipped, and they fell into the great
centre-basins. They had to climb up again, and there they fell again.
They experienced terrible fatigue, which made them feel as if all their
limbs had been dissolved in the water while swimming. Their eyes closed;
they were in the agonies of death.

Spendius struck his hand against the bars of a grating. They shook it,
it gave way, and they found themselves on the steps of a staircase. A
door of bronze closed it above. With the point of a dagger they moved
the bar, which was opened from without, and suddenly the pure open air
surrounded them.