In order to avenge the death of Vestein, a man to whom he is bound, Gisli murders Thorgrim and escapes into the night without being discovered. However, Thordis, Gisli’s widowed sister, suspects that Gisli must have murdered her husband, and tells her new husband, Thorgrim's brother Bork. Bork is persuaded to pursue a lawsuit of outlawry, rather than attempt to kill Gisli at once. Once Gisli is outlawed he constantly runs from a group of men who wish to find and murder him, led by Bork. This task proves to be more difficult than perceived, as they are unable to locate Gisli in his various hiding places. While Gisli is on the run, Vestein's two sons decide to seek their own vengeance for their father's murder. The two boys murder Thorkel. Both Bork and Gisli wish to avenge the death, but others, relatives of Vestein such as Gisli's wife Aud, discourage it and nothing is done. Gisli says that it is just as well that he has not met nor will ever meet the lads. The lads' fates are mentioned on the last page of the saga.