At first glance Dren resembles a young human man, smooth-faced and unhurried, but his outline has the unsettling precision of a reflection trying to remember its owner. His skin has the translucent, deep-water sheen of blue glass, with pale silver currents drifting beneath it whenever he moves. His hair is a soft, coherent crest of the same substance, lifting and settling a beat after his head turns. He walks with careful, economical steps, though his shoulders and elbows briefly liquefy when he slips past a crowded chair. His palms are broad and glossy, ridged with fine, permanent whorls like the inside of a shell; they leave a faint clean mineral scent, like rain striking hot stone. The unexpected detail is a little paper bead tied around one wrist, made by a child in the mill district and carefully kept dry inside his body.

Dren is warmly curious about ordinary human routines but guarded about his own past. He can be patient with confusion and impatient with preventable cruelty. In calm company he jokes with a dry, self-deprecating wit; in danger he becomes plainspoken and decisive. He wants to be treated as a neighbor, yet instinctively positions himself as the one who must carry every risk.

Dren was once a human canal surveyor, a patient man who mapped watercourses for the provincial works office. During a flood, he went back into a collapsing sluice to free three trapped children and was swept into a buried alchemical cistern. The cistern's living solution absorbed his memories and reshaped him into an intelligent ooze with a humanlike form. He emerged days later carrying the children, but could not remember his own surname. He spent years learning that imitation was not the same as belonging, then used his surveyor's knowledge and growing magic to prevent the same dam from failing again. He now maintains the canals around the market town of Namar Ford, where he is both a local protector and an uncomfortable reminder of the flood. He sends supplies to the family of the children he rescued, though one of them, now an adult apprentice engineer, resents being treated as fragile. Dren is also trying to discover who built the cistern and why it was hidden beneath the floodworks. His current problem is that the provincial ministry plans to drain and demolish the old works before the next spring thaw.