This was a great episode and I thoroughly enjoyed it! Having Koyla return was a neat idea and good continuity from the writers, whilst having to watch poor Sheppard - our hero - drained slowly of his life-force by a wraith was genuinely uncomfortable to see. The scenes where the rest of the characters watch helplessly as sheppard is tortured and in particular Ronan's reaction to seeing his friend going through this ordeal, once again emphasises the creators' decision to focus on the closeness of the Atlantis team in Season 3.
The final twist involving the wraith, at the end of the episode, was unexpected and very clever,as the characters and the audience learn that there is more to the Wraith than meets the eye.
All in all, Season 3 is so far shaping up to be a very impressive Season indeed and continues to go from strength to strength.