A sojourn is a ritualistic and sacred part of Shotet culture. Once a season, after a week-long Sojourn Festival, all the able-bodied and of-age Shotet people travel in a special sojourn shlip to chase the current’s Path until the current turns deep blue. Then they descend on a planet and scavenge things the local people no longer need, before returning home.
The decision of where to go is made in part by the Examiners, who consult a model of the solar system to help decide where the current flows. Ryzek overrules the Examiners in wanting to go to Pitha.