Spice and Wolf, Vol. 6 (manga)

Lawrence decides to accompany Holo to Yoitsu, if only to put off that end just a bit longer. Following Eve, the two take a ship downriver from the port of Lenos. On the way, they meet Col, a boy who then becomes entangled in some kind of trouble at a checkpoint along the river. An unexpected turn of events leads Lawrence to save the boy.