So, my internet just got back after, like, almost an entire day. I'm 100% cheating today so I can make sure stuff comes out as close to on time as possible going forwards, since I'm fairly behind right now.
I present Wikipedia:
In the flashforwards, Mia and William follow Felicity's coordinates to Galaxy One headquarters. They are almost caught, but are saved by Connor, who reveals himself as an agent of Knightwatch, a "good version of A.R.G.U.S."
Meanwhile, Rene confronts Dinah, Roy, and Zoe, revealing that Galaxy One plans to blow up Star City to rebuild it like the Glades, but the city will be evacuated beforehand. The three discover that a terrorist organization named Eden Corps, that uses Galaxy One as a front, paid the SCPD to fake Felicity's death.
Mia, William, and Connor enter the headquarters' sublevels, where they find an imprisoned Felicity who claims that the building houses the bombs to be used on Star City.
The others reunite with the group before they meet Rene, who has learned that the bombs are already on-site and that there are no plans to evacuate.
The group infiltrates a party where Mia destroys an electronic device held by Galaxy One head Keven Dale, disabling the bombs. Dale unveils a helmet that would enable Galaxy One to take the Archer program global.
Felicity makes amends with Mia, stating that her grudge with Galaxy One is personal.
This episode was really fun (but stressful and tense!). I wish I had the time to write the description myself. Sigh.