Amanda Tapping did a really great job this episode especially since she was by herself most of the episode. Robin Dunne also did a good job as a much different Will. The creatures were freaky, but I couldn't understand why it seemed some wore goggles.
The story was well written and it was heart wrenching to see Magnus realize she was patient zero. The declaration by Will that he and Kate had a baby was random and quite forced. From now on, we expect something to happen between them which could have ended with simple flirting. I did like the reference to Druitt suicide bombing a week after Magnus died.
My biggest problem with the episode was the overuse of split screen. While I haven't like it the entire season, this episode was really the last straw. There was split screen after split screen, and they did show anything other than different angles. They weren't dramatic or creative, so I wonder that the producers are thinking. It's the same thing with the slo mo fighting sequences. You'd think the producers realize they're lame, but they insist on putting a couple in each episode.