“Vitas Mortis” is episode two of season two of Farscape.
D’Argo, Crichton and Zhaan are visiting a planet where there is supposed to be a Luxan present. There is, a Luxan priestess who wants D’Argo to assist her with her death, something Crichton is not enamoured with, as it poses a risk to D’Argo himself. The crew are much closer to each other than they were at the beginning (after all, D’Argo did try to kill Crichton once in a fit of hyperrage in “Thank God It’s Friday. Again” so Crichton caring about his safety is a definite improvement).
The ritual actually results in the priestess regaining her youth – not the first person who possesses rather unusual powers, powers that seem unconnected to technology and more akin to magic than anything else. Some of the stuff encountered seems more magical than technological in nature. Things start going wrong on Moya, though, and the two things are connected.