In Haven of 2085, Arushka rides Moshi, her black mare, through the Riverlands. She's inspecting the contented Animals which she and Noah have transported to the future to avoid extinction. Dolly follows at a distance… But we see the faithful sheepdog distracted and lured away.

Above the North Col of 2020, the Impact Winter produced by the Nemesis Comet still prevails. Noah discovers Dolly, terrified and half frozen in the blizzard. How had the dog travelled back through time and who sent her?

Arushka returns to the compound, where the Nomads now live as a settled community. With their enemies vanquished and the contentious mineral Thunderstone wiped from the face of the Earth, Haven is a peaceful place. An eccentric old peddler, Monsoon, visits with gossip about the comings and goings of new settlers and about the weather, which in Haven has lately been extreme and unpredictable.

Dolly is discovered in North Col by the authorities and is condemned to banishment in the snow. To save her, Noah breaks the new rules which ban time- travel. He breaks into the sealed Holodeck and used the PH-Ts to return again, with Dolly, to Haven.

He arrives at the height of the storm and helps the Nomads save their hut from a lightning-felled tree. Then there's time for a reunion. But the Dolly mystery is unexplained and some unidentified figures are watching them through the trees.