After Black Zetsu escaped the strata beneath the Land of Rain, for the first time, he failed to take all his traces with him.
On a rock face at the border, three gleaming black footprints remained in the morning light.
The footprints did not resemble human feet.
They looked more like shapes a mass of liquid had barely managed to hold upon landing.
When sunlight struck them, their outermost layers began to contract.
Their interiors, however, did not merge into the rock.
Without chakra of the same origin as Kaguya's, Black Zetsu could no longer make physical materials treat him as part of themselves.
He could still enter narrow crevices.
He could still suppress his fluctuations.
But every movement now had to leave traces of physical weight.
The Land of Rivers recorders did not collect the entire rock face.
The black traces might still possess someone.
They used only ordinary wooden rulers to record the depth and spacing, then removed a single fragment with no active response from the outer edge of a footprint.
The fragment was divided into three portions.
The Land of Rain confirmed that it matched the fissure in the sixth Empty Slot.
Konoha confirmed that it did not belong to any existing secret shadow technique.
The remaining portion stayed where it was, with border residents witnessing where it was sealed.
Black Zetsu's first stretch of physical movement was thus established.
He had moved eleven li north from the Land of Rain.
He then vanished at the border between the Land of Fire and the Land of Grass.
Both countries demanded authority over the pursuit.
The Land of Fire believed the route might lead to Konoha's old archives.
The Land of Grass pointed out that the footprints lay near one of its villages, and a large-scale entry