The motes are expanding

The Water mote lies in the sodden forest of Gaba Alam, and its wet cold used to carry a mile or two. Four days’ walk from the Twisted Grove to Loshev, with three keeps broken behind them, the Valiant Few picked it up from a good distance outside that.

The reach is what they observed. The explanation is theirs, and they did not settle it. The reading they argued for is that the motes have begun to widen, because the positive and negative energies that had ground against each other over Idir collapsed in together and left more planar room to press into. Set against that is the plainer possibility they raised themselves, that they had simply passed nearer the water than on any earlier crossing. Mikhail would not have it looked into. He nearly drowned in that place, though what he said out loud was that it was a distraction, and they walked on.

From the map rooms in the keeps they know roughly where every mote sits. The version of it that frightens them is motes widening until they reach one another, and a band of ground with two planes coming through it standing across a country that people have to cross.