The Lake You Can Farm in Summer

Every June, the Lake of Cirknitz in Illyria empties itself. The water drains away through fissures in its own basin, and the peasants move in behind it, sowing a crop on the lake bottom and pasturing herds on the rich herbage its oozy bed soon produces. The harvest is carried off by the end of September^[1].

Around the middle of October the water comes back, spouting up with great force through several openings in the earth, and it brings fish with it. It also brings a stranger animal, which the book calls the Syren: the pale, blind creature that lives in the underground river running through the Cavern of Adelsberg. Its arrival in the returning flood was taken as proof that the lake and the cavern draw on the same hidden water.