Like most of the Season 3 Xindi episodes, Rajin is fast-moving and interestingly plotted - successfully producing a sense of urgency. This is a well-directed and well-shot episode. The acting is mostly fairly good. Nikita Ager plays Rajiin and does a passable job.
The story picks up within the Xindi story arc. The crew continues to work on a way to adapt the ship to the anomalies of the expanse, and Archer's nerves are on the ragged edge. While away on a shopping trip, Archer encounters a female slave who seems hell-bent on accompanying him back to Enterprise. She escapes her bonds, runs to Archer for protection, and the away team defends her.
Once Rajin is on board, it seems as if the episode is going to be yet another Enterprise exploitation of an attractive female, but the plot eventually takes surprisingly interesting turn which I won't spoil here.
Recommended, but only if you've seen the earlier parts of Season 3.
This is the season that sealed Enterprise's fate. The franchise decided to begin a complex DS9-length story-arc at the end of Season 2, which would span most of season 3. While not unprecedented among ST shows, this was certainly unprecedented in Enterprise. Trekkies became disturbed by the distant departure from the canon which was required by the Delphic Expanse and the Xindi episodes, and the show's dwindling audience, many of whom began their ST interests with Enterprise, didn't know what to make of it. Despite the fact that the quality of drama on the show was steadily improving, it's ratings steadily declined.