Spoiler Level: High
Dodo birds!!! Awww, they're so cute!! Were dodos really this cute in real life? It makes me sad that we'll never know. It's a shame some of them couldn't have stayed and repopulated the species, like the humpback whales in Star Trek IV.
For a minute there I thought we were going to have just a character episode, finding out Helen's story, watching the relationship between Connor, Abby and Stephen unfold, seeing Connor's friends close in on the truth, with the dodo birds being the only creature to come through the Anomaly. But then the parasite had to go and (literally) rear its ugly head and give us a real threat, turning the story into a tragedy. Needless to say it's easy to relate to Tom and Duncan, and it was fun seeing all the stuff in their flat-- for example, I loved how some of the walls were literally wallpapered with comic books, and I'm pretty sure I saw an ALPHIE robot on their desk. They were fun characters, and losing Tom is like losing one of our own.
And the Grand Central Anomaly Station was awesome. I did not see that coming, and it explains how Helen's getting from time period to time period. Very, very cool.