I think we are all clear on the premise of Under the Dome, right? A small town called Chester’s Mill is covered with a giant, clear dome. Nobody knows what it is, where it came from, or why it is here (well, almost no one - we’ll get to that).
More garroted victims turn up, and Stiles discovers a pattern.
The invasion that started last week concludes as the episode opens. Cochise sends his snipers to shoot down a small fleet of Espheni ships, effectively ending the battle.
On a bridge, an inter-dimensional portal opens up, and something is struggling to exit. It succeeds.
In Will’s latest nightmare, he is walking through the woods and finds a bloody tree. Someone - or something - is there. He wakes to discover his dogs whimpering, and discovers his feet are muddy. He stumbles into the kitchen for water and some pills. His vision becomes jittery and he vomits into the sink. That is when he sees a human ear settled next to the drain.
Derek and Scott have split up and spread out through the woods to locate Boyd and Cora. A couple of kids, out catching fireflies, are attacked by Boyd. Scott saves them then takes them home before joining up with Derek to track their missing werewolves.
Charleston is prepping for skitter retaliation with around-the-clock guards posted around the perimeter. Shots ring out, but these are not alien blasters; these are shots from human guns.
The governor starts a war against the vampires as the characters pick up the pieces from last season's explosive finale.
Will has been bonding with Georgia while they are both in the hospital. When Georgia is released from the oxygen tube, she will get shock treatment. Her memories of her “killing spree” are hazy.
Scott and Stiles head to a party. The hostess, Heather, is a childhood friend of Stiles’ and she lures him there with an ulterior motive: she wants Stiles to take her virginity.