THE FIELD STATION / LOGIC EXPEDITIONS
TracewaterHidden Headwaters
Life leaves a trace in the water. Follow it upstream.
Read the river
Each creature lives at exactly one headwater. Traces flow downstream and combine at junctions. In Sample water mode, click any station to reveal which creatures live anywhere upstream of it. A dash means none.
Switch to a creature, then click a numbered headwater to place its pin. Creatures may share a headwater. Use positive AND negative samples to narrow the search, then submit all pins. Fewer samples earn more stars. There is no timer or hard sample limit.
This is a fictional deduction puzzle inspired by 2026 environmental-DNA biodiversity research. Real DNA can decay, drift and persist; these rules deliberately simplify it.
Original MIT game · All art and code local · Research inspiration: UWA, July 2026 ·