It came upon suddenly over about five seconds.
Who did it? Emily? Victoria? Nolan? (I doubt it.) Or that Lizbeth ("Dragon Tattoo") girl that Nolan caugh (and whom he was supposed to bail out of jail)? That sounds more likely?
Is this a cross with "Revolution"? Well, in the NBC series, the power blackout was caused by "nanobot" viruses in the air, an idea that makes no sense in physics. But conventional EMP does make a lot of sense to physicists.
Or was it a massive solar storm? Maybe. A solar storm could cause massive power outages would be less likely to bamboozle electronics already turned off.
If it's EMP, then Nolan's computers are all wiped out, and the new world order will have no use for him. Pardon,. Nolan proved his seamanship was pretty good a few episodes ago. But remember when sister Emily asked "Can you really do this?"
Remember, also, that 'FlashForward" on ABC featured a blackout (looking into the future) based on an idea of quantum physics.
The two-hour finale of "Revenge" will be called "Truth". That's the "Eternal Feminine".