A human colony is attacked.
It is difficult to judge the plot of this one before the story concludes, but it provides good setup and cliffhanger. I am not one to complain (much) about writers breaking continuity with previous Trek when the story is good, but the arc involving these particular antagonists will need to have a very good conclusion in light of how much revision of backstory appears to be happening prior to the events of a classic episode of the original series.
As for the species portrayal in SNW, there is a bit too much "Alien" similarities for me, and so far they appear to be one of those classic Trek baddies that have implausibly developed space travel. However, I accept there could be more backstory and explanation to come.
The characters are mostly used well, particularly the reintroduction of a classic who fits nicely into the mix and is played strongly by Martin Quinn. This is the best aspect of the episode for me.
As always the visuals, art design and effects are of a very high standard.