By Sorrow's River continues the Berrybender party's trail across the endless Great Plains of the West toward Santa Fe, where they intend, those who are lucky enough to survive the journey, to spend the winter. They meet up with a vast array of characters from the history of the West: Kit Carson, the famous scout; Le Partezon, the fearsome Sioux war chief; two aristocratic Frenchmen whose eccentric aim is to cross the Great Plains by hot air balloon; a party of slavers; a band of raiding Pawnee; and many other astonishing characters who prove, once again, that the rolling, grassy plains are not, in fact, nearly as empty of life as they look. Most of what is there is dangerous and hostile, even when faced with Tasmin's remarkable, frosty sangfroid.