Farscape - Season 4, Collection 1 (Starburst Edition) - Region 1 DVD

After a forced landing, the crew is separated by an elaborate trap that leaves Crichton, D'Argo, Noranti and Rygel in a lava-filled system of underground caves. While Chiana and Sikozu are on the surface trying to reactivate D'Argo's ship, Crichton and the others are being hunted down by mercenaries who are led by a monster impervious to the fiery lava.