This episode reveals more of the power of goa'uld sarcophagi. The team are captured on a naquahdah-mining world and enslaved in the mines by the ruler of the planet. A failed escape attempt leaves Daniel critically injured in a rockfall, and he is revived in a sarcophagus by the planet's princess, daughter of the 'god slayer', the old ruler. She convinces Daniel to keep using the sarcophagus even when healthy, which has an addictive, narcotic effect on him. This means he has difficulty remembering he's supposed to be helping his friends, who are really struggling in the mines, but he eventually does arrange for them to be set free and return to Earth to arrange things for his impending wedding to the princess. When back on Earth, he experiences severe withdrawal symptoms, but eventually comes back to normal and the team return to the planet so he can explain that he can't go through with the wedding.
We learn that the sarcophagus has this personality-changing effect on repeat users, and can extend longevity a great deal, as the god-slayer is hundreds of years old. We also learn, in continuation from the previous episode, that Sam's blending with Jolinar had lasting effects; she 'senses' that the old man in charge isn't a goa'uld - or more specifically, doesn't get a sense of a goa'uld within him. She revelas that lately she's been getting a 'funny feeling' when she's around Teal'c (quoth Jack: "Hey, who doesn't?"). She also has a dream/vision where she 'remembers' that the tok'ra don't use sarcophagi, and speculates that the overuse of them could be what drove the goa'uld power-mad.
There's one line that stands out to me in this episode. When Jack is trying to calm Daniel down during his withdrawal-fueled rampage, he looks him right in the eyes and tells him, "I know what it's like." This suggests more dark periods in Jack's past - in Prisoners he mentions he was in prison, and now he implies he's been a drug addict in the past, too. Maybe the two were related, and perhaps the drug use was to try and get through some of the black ops stuff he's seen and done (as mentioned in Cor-Ai and Solitudes, and shown in The Gamekeeper).